parse-util: refuse leading white space in port number

When parse_ip_port() is directly used in a conf parser, then that's
fine, as the rvalue is already truncated.

When parse_ip_port() is used when e.g. parsing IP address with port,
then we should really refuse white space after colon.

src/basic/parse-util.c

@@ -644,7 +644,7 @@ int parse_ip_port(const char *s, uint16_t *ret) {
         uint16_t l;
         int r;
 
-        r = safe_atou16(s, &l);
+        r = safe_atou16_full(s, SAFE_ATO_REFUSE_LEADING_WHITESPACE, &l);
         if (r < 0)
                 return r;