stop readline from overwriting LINES

The problem was that readline would completely block LINES from updating
after prompting the user. I'm not entirely sure why this happened, but
at least this patch fixes the problem.

src/nnn.c

@@ -4783,6 +4783,7 @@ int main(int argc, char *argv[])
 	setlocale(LC_ALL, "");
 
 #ifndef NORL
+	rl_change_environment = 0;
 	/* Bind TAB to cycling */
 	rl_variable_bind("completion-ignore-case", "on");
 #ifdef __linux__