Fix plural form of translations.

The leading '_n: ' should not be part of the translations.

tde-i18n-nl/messages/tdebase/kcminput.po

@@ -427,7 +427,7 @@ msgid ""
 "_n:  pixel\n"
 " pixels"
 msgstr ""
-"_n: pixel\n"
+"pixel\n"
 " pixels"
 
 #: mouse.cpp:779
@@ -435,7 +435,7 @@ msgid ""
 "_n:  line\n"
 " lines"
 msgstr ""
-"_n:  regel\n"
+" regel\n"
 "  regels"
 
 #: tdesyndaemon.cpp:186 tdesyndaemon.cpp:187