Bugfix sending of typing events

src/controllers/molecules/MessageComposer.js

@@ -351,15 +351,22 @@ module.exports = {
     },
 
     stopUserTypingTimer: function() {
+        if (this.userTypingTimer) {
             clearTimeout(this.userTypingTimer);
+            this.userTypingTimer = null;
+        }
     },
 
     startServerTypingTimer: function() {
+        if (!this.serverTypingTimer) {
             var self = this;
             this.serverTypingTimer = setTimeout(function() {
+                if (self.isTyping) {
                     self.sendTyping(self.isTyping);
                     self.startServerTypingTimer();
+                }
             }, TYPING_SERVER_TIMEOUT / 2);
+        }
     },
 
     stopServerTypingTimer: function() {