i18n: Better naming

s isnt much of a name for a variable.

coalib/misc/i18n.py

@@ -75,14 +75,15 @@ def _get_locale():  # pragma: no cover
 translation = gettext.translation(COALA_DOMAIN, fallback=True)
 
 
-def _(s):
+def _(original):
     """
     Marks the input string for translation and returns the translated string.
     """
-    return translation.gettext(s)
+    return translation.gettext(original)
 
-def N_(s):
+
+def N_(original):
     """
     Marks the input string for translation and returns the untranslated string.
     """
-    return s
+    return original