Fix Keystroke lost in favorites pane issue

If user is in favorites pane -> starts typing, first character is lost
This is because the changeTab->focusSearchEntry->set_text("")
Not sure if right way, but fixing this by setting the text to its prev
value after the changeTab, works well for me

usr/lib/linuxmint/mintMenu/plugins/applications.py

@@ -811,8 +811,10 @@ class pluginclass( object ):
             if self.donotfilterapps:
                 widget.set_text( "" )    
             else:
+                text = widget.get_text()
                 if self.lastActiveTab != 1:
                     self.changeTab( 1 )
+                    widget.set_text( text ) 
                 text = widget.get_text()
                 showns = False # Are any app shown?
                 shownList = []