fix bad cast

git-svn-id: svn://svn.savannah.gnu.org/nano/trunk/nano@2168 35c25a1d-7b9e-4130-9fde-d3aeb78583b8

src/nano.c

@@ -3594,7 +3594,7 @@ void do_output(int *kbinput, size_t kbinput_len)
 	} else {
 #endif
 	    key_len = 1;
-	    key[0] = (char)kbinput[i];
+	    key[0] = (unsigned char)kbinput[i];
 #ifdef NANO_WIDE
 	}
 #endif