Fix exception in set operation of sogo-tool

NEWS

@@ -16,7 +16,8 @@ Bug fixes
  - (regression) fixed sending a message when mail module is not active (#3088)
  - mail lables with blanks are not handled correctly (#3078)
  - fixed BlackBerry issues sending multiple mails over EAS (#3095)
- - fixed plain/text mails showing on one line on Android/EAS (#3055) 
+ - fixed plain/text mails showing on one line on Android/EAS (#3055)
+ - fixed exception in sogo-tool when parsing arguments of a set operation
 
 2.2.15 (2015-01-30)
 -------------------

Tools/SOGoToolUserPreferences.m

@@ -254,7 +254,7 @@ typedef enum
                  //
                  // to achieve what we want.
                  //
-                 if (o && [o count] == 1)
+                 if (o && [o isKindOfClass: [NSDictionary class]] && [o count] == 1)
                   {
                     [source setObject: [[o allValues] lastObject] forKey: key];
                   }