Cosmetic changes to common_redirect, clientError, serverError

Since these functions exit (or throw exception) after running, there
is no need to have a 'return' statement or similar afterwards.

plugins/OStatus/OStatusPlugin.php

@@ -281,7 +281,6 @@ class OStatusPlugin extends Plugin
 
                 // redirect to the new profile.
                 common_redirect(common_local_url('tagprofile', array('id' => $oprofile->profile_id)), 303);
-                return false;
 
             } catch (Exception $e) {
                 // TRANS: Error message in OStatus plugin. Do not translate the domain names example.com

plugins/OStatus/actions/groupsalmon.php

@@ -145,7 +145,6 @@ class GroupsalmonAction extends SalmonAction
         if (Group_block::isBlocked($this->group, $profile)) {
             // TRANS: Client error displayed when trying to join a group the user is blocked from by a group admin.
             $this->clientError(_m('You have been blocked from that group by the admin.'), 403);
-            return false;
         }
 
         try {

plugins/OStatus/actions/ostatustag.php

@@ -38,7 +38,6 @@ class OStatusTagAction extends OStatusInitAction
         if (common_logged_in()) {
             // TRANS: Client error displayed when trying to list a local object as if it is remote.
             $this->clientError(_m('You can use the local list functionality!'));
-            return false;
         }
 
         $this->nickname = $this->trimmed('nickname');