Fix some issues with admin self settings (librenms#15332)

Don't require old password when not settings password
Show old password field for user's own user

app/Http/Requests/UpdateUserRequest.php

@@ -81,8 +81,8 @@ public function withValidator($validator)
             // if not an admin and new_password is set, check old password matches
             $user = $this->route('user');
             if ($user && $this->user()->can('update', $user) && $this->user()->is($user)) {
-                if ($this->has('new_password')) {
-                    if ($this->has('old_password')) {
+                if ($this->get('new_password')) {
+                    if ($this->get('old_password')) {
                         $user = $this->route('user');
                         if ($user && ! Hash::check($this->old_password, $user->password)) {
                             $validator->errors()->add('old_password', __('Existing password did not match'));

resources/views/user/form.blade.php

@@ -60,9 +60,9 @@
     <div class="form-group @if($errors->hasAny(['old_password', 'new_password', 'new_password_confirmation'])) has-error @endif">
         <label for="password" class="control-label col-sm-3">{{ __('Password') }}</label>
         <div class="col-sm-9">
-            @cannot('admin')
+            @if(auth()->user()->cannot('admin') || auth()->user()->is($user))
                 <input type="password" class="form-control" id="old_password" name="old_password" placeholder="{{ __('Current Password') }}">
-            @endcannot
+            @endif
             <input type="password" autocomplete="off" class="form-control" id="new_password" name="new_password" placeholder="{{ __('New Password') }}">
             <input type="password" autocomplete="off" class="form-control" id="new_password_confirmation" name="new_password_confirmation" placeholder="{{ __('Confirm Password') }}">
             <span class="help-block">