Fix: parse string to float to compare versions

Author: nlpsuge

metadata.json

@@ -9,5 +9,5 @@
     ],
     "url": "https://github.com/nlpsuge/gnome-shell-extension-another-window-session-manager",
     "uuid": "another-window-session-manager@gmail.com",
-    "version": 12
+    "version": 13
   }

utils/gnomeVersion.js

@@ -1,10 +1,13 @@
 const Config = imports.misc.config; 
 
-const GNOME_VERSION = Config.PACKAGE_VERSION;
+// '41.beta' => 41
+// '41.4' => 41.4
+// '3.38.beta' => 3.38
+const GNOME_VERSION = parseFloat(Config.PACKAGE_VERSION);
 
 
 function isOlderThan42() {
-    return GNOME_VERSION < '42';
+    return GNOME_VERSION < 42;
 }