Php – SQLSTATE[HY000]: General error: 1364 Field ‘photo’ doesn’t have a default value in laravel 5.5

I am trying to upload users photo during registration, but I am getting this error, I searched online and founded possible solutions did not work for me. I am using sentinel package for advanced authentication. Please anyone help me .
Here is my controller-

 public function postRegister(Request $request){
    $request->validate([
        'first_name' => 'required|max:255',
        'last_name' => 'required|max:255',
        'user_name' => 'unique:users|max:255',
        'email' => 'required|unique:users|email|max:255',
        'password' => 'required|min:6|confirmed',
        'phone' => 'required|numeric',
    ]);
    //upload image
    if ($file = $request->file('photo')) {
        $fileName = $file->getClientOriginalName();
        $extension = $file->getClientOriginalExtension() ?: 'png';
        $folderName = '/uploads/users/';
        $destinationPath = public_path() . $folderName;
        $safeName = str_random(10) . '.' . $extension;
        $file->move($destinationPath, $safeName);
        $request['photo'] = $safeName;
    }

    // $user = Sentinel::registerAndActivate($request->all());
    $user = Sentinel::registerAndActivate($request->all());
    // dd($user);
    //$activation = Activation::create($user);

    $role = Sentinel::findRoleBySlug('member');

    $role->users()->attach($user);
    //$this->sendEmail($user, $activation->code);
    //return redirect('/login');
    return ('You have seccsessfully registered. Now login to start');
}

And form input-(with enctype="multipart/form-data" top of the form)

 <div class="row">
    <div class="col-md-6">
      <div class="sponsor-row">
        <label for="sponsor_input"><i class="fa fa-tags"></i></label>
        <input type="text" name="sponsor" id="sponsor_input" class="sponsor-input" placeholder="Sponsor"></input>
      </div>
    </div>
    <div class="col-md-6">
      <div class="photo-row">
        <label for="photo_input"></label>
        <input type="file" name="photo" id="photo" class="photo-input"></input>
      </div>
    </div>
  </div>
</div>

My User Model is:

<?php

namespace App;

use Illuminate\Notifications\Notifiable;
use Illuminate\Foundation\Auth\User as Authenticatable;

class User extends Authenticatable
{
use Notifiable;

/**
 * The attributes that are mass assignable.
 *
 * @var array
 */
protected $fillable = [
    'first_name', 'last_name', 'user_name','email', 'password', 'phone', 'location', 'sponsor', 'photo',
];

/**
 * The attributes that should be hidden for arrays.
 *
 * @var array
 */
protected $hidden = [
    'password', 'remember_token',
];

}

My Migration Code is:

Schema::create('users', function (Blueprint $table) {
        $table->increments('id');
        $table->string('first_name')->nullable();
        $table->string('last_name')->nullable();
        $table->string('user_name');
        $table->string('email');
        $table->string('password');
        $table->string('phone');
        $table->string('location');
        $table->string('sponsor');
        $table->binary('photo')->nullable();
        $table->text('permissions')->nullable();
        $table->timestamp('last_login')->nullable();
        $table->timestamps();

        $table->engine = 'InnoDB';
        $table->unique('email');
    });