Change Usage translation in japanese, this is what gtk uses

diff --git a/po/ja.po b/po/ja.po
index 4af2e9b..31a070f 100644 (file)
--- a/po/ja.po
+++ b/po/ja.po
@@ -296,7 +296,7 @@ msgstr "著作権 (c)"
 
 #: openbox/openbox.c:529
 msgid "Syntax: openbox [options]\n"
-msgstr "使い方: openbox [オプション]\n"
+msgstr "用法: openbox [オプション]\n"
 
 #: openbox/openbox.c:530
 msgid ""