BUG/MINOR: http-fetch: recognize IPv6 addresses in square brackets in req.hdr_ip()

If an IPv6 address is enclosed in square brackets [], trim them before
calling inet_pton().  This is to comply with RFC7239 6.1 and RFC3986 3.2.2.
diff --git a/src/http_fetch.c b/src/http_fetch.c
index 8c01e03..f855a67 100644
--- a/src/http_fetch.c
+++ b/src/http_fetch.c
@@ -1024,7 +1024,15 @@
 				/* IPv4 address suffixed with ':' followed by a valid port number */
 				smp->data.type = SMP_T_IPV4;
 				break;
+			} else if (temp->area[0] == '[' && temp->area[smp->data.u.str.data-1] == ']') {
+				/* IPv6 address enclosed in square brackets */
+				temp->area[smp->data.u.str.data-1] = '\0';
+				if (inet_pton(AF_INET6, temp->area+1, &smp->data.u.ipv6)) {
+					smp->data.type = SMP_T_IPV6;
+					break;
+				}
 			} else if (inet_pton(AF_INET6, temp->area, &smp->data.u.ipv6)) {
+				/* plain IPv6 address */
 				smp->data.type = SMP_T_IPV6;
 				break;
 			}