when using slang, call the right function to enable UTF-8 support

git-svn-id: svn://svn.savannah.gnu.org/nano/trunk/nano@2350 35c25a1d-7b9e-4130-9fde-d3aeb78583b8

src/nano.c

@@ -3939,7 +3939,7 @@ int main(int argc, char **argv)
 
 #ifdef USE_SLANG
 	if (!ISSET(NO_UTF8))
-	    SLsmg_utf8_enable(TRUE);
+	    SLutf8_enable(TRUE);
 #endif
     }
 #else