Make a copy of the translated text

Otherwise the translation will get freed (and often reused) before it
makes it to the screen.
The problem with this is that it leaks memory for every translation.

Reported-by: Robert C. Helling <helling@atdotde.de>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

gettextfromc.cpp

@@ -4,7 +4,7 @@
 
 char *gettextFromC::gettext(const char *text)
 {
-	return tr(text).toLocal8Bit().data();
+	return strdup(tr(text).toLocal8Bit().data());
 }
 
 gettextFromC* gettextFromC::instance()