Reset idling flag when cancelling early due to being cancelled.

Change-Id: Idde5f3a3fa04a1aa80ef4cdb9e3ba1ab01d3fcb5

provider_src/com/android/email/mail/store/ImapFolder.java

@@ -251,6 +251,7 @@ public class ImapFolder extends Folder {
                     // the server to listen for new changes)
                     synchronized (mIdleSync) {
                         if (mIdlingCancelled) {
+                            mIdling = false;
                             return;
                         }
                     }