tsumego solver 5000 is go

i18n.py

@@ -101,12 +101,13 @@ for lang in locales:
     print("Fixed", pofile[lang], "and converted ->", mofile)
 
 
-for file in glob.glob("katrain/**/*.py") + glob.glob("katrain/**/*.kv"):
+for file in glob.glob("**/*.py") + glob.glob("**/*.kv"):
     with open(file, "r") as f:
         for i, line in enumerate(f.readlines()):
             matches = [m.strip() for m in re.findall(r"i18n._\((.*?)\)", line)]
             for msgid in matches:
-                if msgid[0] in ['"', "'"] and msgid.strip("\"'") not in strings_to_langs:  # not code
+                stripped_msgid = msgid.strip("\"'")
+                if stripped_msgid and msgid[0] in ['"', "'"] and stripped_msgid not in strings_to_langs:  # not code
                     print(f"Missing {msgid} used in code at \t{file}:{i} \t'{line.strip()}'")
                     errors += 1