Add missing el/Greek entry

Remove bad "ur" listing

Author: NSoiffer

addon/globalPlugins/MathCAT/MathCATPreferences.py

@@ -108,6 +108,7 @@ def LanguagesDict():
             "dv": "ދިވެހިބަސް",
             "dz": "རྫོང་ཁ",
             "ee": "Ɛʋɛ",
+            "el": "Ellêniká",
             "en": "English",
             "eo": "Esperanto",
             "es": "Español",
@@ -116,7 +117,6 @@ def LanguagesDict():
             "fj": "Na Vosa Vakaviti",
             "fo": "Føroyskt",
             "fr": "Français",
-            "ur": "Furlan",
             "fy": "Frysk",
             "ga": "Gaeilge",
             "gd": "Gàidhlig",