Changed escape key from ^g to ^t

After renaming to "tio" it makes sense to change the escape key
accordingly. Hence, the new escape key is ^t.

Meaning, in session, its now ctrl-t + q to quit.

src/options.c

@@ -57,7 +57,7 @@ void print_options_help(char *argv[])
     printf("  -v, --version               Display version\n");
     printf("  -h, --help                  Display help\n");
     printf("\n");
-    printf("In session, press ctrl-g + q to quit.\n");
+    printf("In session, press ctrl-t + q to quit.\n");
     printf("\n");
 }