Fix handling of priority mail header

NEWS

@@ -30,9 +30,10 @@ Bug fixes
  - [web] show the To instead of From when we are in the Sent folder (#3547)
  - [web] fixed handling of mail tags in mail viewer
  - [web] avoid marking mails as read when archiving a folder (#2792)
+ - [web] fixed crash when sending a message with a special priority
+ - [dav] we now handle the default classifications for tasks (#3541)
  - [eas] properly unfold long mail headers (#3152)
  - [eas] correctly set EAS message class for S/MIME messages (#3576)
- - [dav] we now handle the default classifications for tasks (#3541)
  - [eas] handle FilterType changes using EAS (#3543)
  - [eas] handle Dovecot's mail_shared_explicit_inbox parameter
  - [eas] prevent concurrent Sync ops from same device (#3603)

SoObjects/Mailer/SOGoDraftObject.m

@@ -307,11 +307,7 @@ static NSString    *userAgent      = nil;
     {
       // newHeaders come from Web form; convert priority to MIME header representation
       priority = [newHeaders objectForKey: @"priority"];
-      if (!priority || ![priority length] || [priority intValue] == 3)
-        {
-          [headers removeObjectForKey: @"X-Priority"];
-        }
-      else if ([priority intValue] == 1)
+      if ([priority intValue] == 1)
         {
           [headers setObject: @"1 (Highest)"  forKey: @"X-Priority"];
         }
@@ -323,10 +319,14 @@ static NSString    *userAgent      = nil;
         {
           [headers setObject: @"4 (Low)"  forKey: @"X-Priority"];
         }
-      else
+      else if ([priority intValue] == 5)
         {
           [headers setObject: @"5 (Lowest)"  forKey: @"X-Priority"];
         }
+      else
+        {
+          [headers removeObjectForKey: @"X-Priority"];
+        }
       if (priority)
         {
           [headers setObject: priority  forKey: @"priority"];