Merge branch 'PHP-7.0' into PHP-7.1

* PHP-7.0:
  acinclude.m4: fix krb5-config detection and usage in PHP_SETUP_KERBEROS.
  Add more mbfl string size checks (bug #73505)

acinclude.m4

@@ -2264,7 +2264,7 @@ AC_DEFUN([PHP_SETUP_KERBEROS],[
   fi
 
   dnl If krb5-config is found try using it
-  if test "$PHP_KERBEROS" = "yes" && test -x "$KRB5_CONFIG"; then
+  if test "$PHP_KERBEROS" != "no" && test -x "$KRB5_CONFIG"; then
     KERBEROS_LIBS=`$KRB5_CONFIG --libs gssapi`
     KERBEROS_CFLAGS=`$KRB5_CONFIG --cflags gssapi`