i3-nagbar: add missing newline when printing version information

i3-nagbar/main.c

@@ -341,7 +341,7 @@ int main(int argc, char *argv[]) {
     while ((o = getopt_long(argc, argv, options_string, long_options, &option_index)) != -1) {
         switch (o) {
             case 'v':
-                printf("i3-nagbar " I3_VERSION);
+                printf("i3-nagbar " I3_VERSION "\n");
                 return 0;
             case 'f':
                 FREE(pattern);