Description: Add check of environmental variable to disable all network
tests during the build process.

--- a/t/testload.pm
+++ b/t/testload.pm
@@ -82,6 +82,10 @@
 sub network_ok {
   if (! defined $Network_Up) {
     my %ua_parms;
+    if ($ENV{disable_network_tests}) {
+      $Network_Up = 0;
+      return $Network_Up;
+    }
     if ($ENV{http_proxy}) {
       $ua_parms{env_proxy} = 1;
     }