[feature/avatars] Inform user of no available local avatars

Rather than showing the user an empty drop-down list for the local avatar
categories, inform him/her that there are currently no (local) avatars
available.

PHPBB3-10018

phpBB/language/en/common.php

@@ -396,6 +396,7 @@ $lang = array_merge($lang, array(
 	'NO_AUTH_ADMIN'				=> 'Access to the Administration Control Panel is not allowed as you do not have administrative permissions.',
 	'NO_AUTH_ADMIN_USER_DIFFER'	=> 'You are not able to re-authenticate as a different user.',
 	'NO_AUTH_OPERATION'			=> 'You do not have the necessary permissions to complete this operation.',
+	'NO_AVATARS'				=> 'No avatars currently available',
 	'NO_CONNECT_TO_SMTP_HOST'	=> 'Could not connect to smtp host : %1$s : %2$s',
 	'NO_BIRTHDAYS'				=> 'No birthdays today',
 	'NO_EMAIL_MESSAGE'			=> 'Email message was blank.',

phpBB/styles/prosilver/template/ucp_avatar_options_local.html

@@ -1,3 +1,4 @@
+<!-- IF .avatar_local_cats -->
 <label for="category">{L_AVATAR_CATEGORY}{L_COLON} <select name="avatar_local_cat" id="category">
 <option value="">{L_NO_AVATAR_CATEGORY}</option>
 <!-- BEGIN avatar_local_cats -->
@@ -14,3 +15,6 @@
 <!-- END avatar_local_col -->
 <!-- END avatar_local_row -->
 </div>
+<!-- ELSE -->
+<p><strong>{L_NO_AVATARS}</strong></p>
+<!-- ENDIF -->

phpBB/styles/subsilver2/template/ucp_avatar_options_local.html

@@ -1,4 +1,5 @@
 <table class="tablebg" width="100%" cellspacing="1">
+	<!-- IF .avatar_local_cats -->
 	<tr> 
 		<td class="cat" colspan="2" align="center" valign="middle"><span class="genmed">{L_AVATAR_CATEGORY}{L_COLON} </span><select name="avatar_local_cat" id="category">
 			<option value="">{L_NO_AVATAR_CATEGORY}</option>
@@ -30,4 +31,9 @@
 			</table>
 		</td>
 	</tr>
+	<!-- ELSE -->
+	<tr>
+		<td class="row1" colspan="2"><strong>{L_NO_AVATARS}</strong></td>
+	</tr>
+	<!-- ENDIF -->
 </table>