Fix use of implode() to avoid warnings when running on newer versions

of PHP.

See also https://www.php.net/manual/en/function.implode.php
Committed with minor changes.

PR:		240931
Submitted by:	lutz@donnerhacke.de

devel/libphutil/Makefile

@@ -2,6 +2,7 @@
 
 PORTNAME=	libphutil
 PORTVERSION=	20190831
+PORTREVISION=	1
 CATEGORIES=	devel
 PKGNAMEPREFIX=	${PHP_PKGNAMEPREFIX}
 

devel/libphutil/files/patch-src_utils_utils.php

@@ -0,0 +1,11 @@
+--- src/utils/utils.php.orig	2019-08-31 14:54:35 UTC
++++ src/utils/utils.php
+@@ -1703,7 +1703,7 @@ function phutil_build_http_querystring_f
+     list($key, $value) = phutil_http_parameter_pair($key, $value);
+     $query[] = rawurlencode($key).'='.rawurlencode($value);
+   }
+-  $query = implode($query, '&');
++  $query = implode('&', $query);
+ 
+   return $query;
+ }