Linux: fix translation issue

gajim/common/i18n.py

@@ -62,8 +62,23 @@ if os.name == 'nt':
     if lang:
         os.environ['LANG'] = lang
 
-#gettext.install(APP, defs.localedir)
-gettext.install(APP)
+    localedir = "../po"
+else:
+    # try to find domain in localedir
+    path = gettext.find(APP)
+    if path:
+        # extract localedir from localedir/language/LC_MESSAGES/domain.mo
+        path, tail = os.path.split(path)
+        path, tail = os.path.split(path)
+        localedir, tail = os.path.split(path)
+    else: # fallback to user locale
+        base = os.getenv('XDG_DATA_HOME')
+        if base is None or base[0] != '/':
+            base = os.path.expanduser('~/.local/share')
+        localedir = os.path.join(base, "locale")
+    locale.bindtextdomain(APP, localedir)
+gettext.install(APP, localedir)
+
 if gettext._translations:
     _translation = list(gettext._translations.values())[0]
 else: