fix typo

Author: flowdas

library/test.po

@@ -555,7 +555,7 @@ msgstr ""
 
 #: /Users/flowdas/works/docs/python-docs-ko/src/Doc/library/test.rst:413
 msgid "Check for presence of docstrings."
-msgstr "독 스트링이 있는지 확인합니다."
+msgstr "독스트링이 있는지 확인합니다."
 
 #: /Users/flowdas/works/docs/python-docs-ko/src/Doc/library/test.rst:418
 msgid "Define the URL of a dedicated HTTP server for the network tests."