Revert downstream change in Net::Config default configuration

This is not needed since upstream commit:

commit adeb94125ab7de8d20c129a905a5159972ad9fd1
Author: Ricardo SIGNES <rjbs@cpan.org>
Date:   Mon Oct 22 05:01:09 2007 -0400

    hostname.t busted
    Message-ID: <20071022130109.GA16748@knight>

    p4raw-id: //depot/perl@32180

Also fixed in CPAN's libnet since 1.22_02.

perl-disable_test_hosts.patch

@@ -1,12 +0,0 @@
-diff -up perl-5.12.0/cpan/libnet/lib/Net/Config.pm.disable perl-5.12.0/cpan/libnet/Net/Config.pm
---- perl-5.12.0/cpan/libnet/lib/Net/Config.pm.disable	2010-01-18 19:52:49.000000000 +0100
-+++ perl-5.12.0/cpan/libnet/lib/Net/Config.pm	2010-04-13 16:03:50.090770813 +0200
-@@ -29,7 +29,7 @@ eval { local $SIG{__DIE__}; require Net:
-   ftp_firewall    => undef,
-   ftp_ext_passive => 1,
-   ftp_int_passive => 1,
--  test_hosts      => 1,
-+  test_hosts      => 0,
-   test_exist      => 1,
- );
- 

perl.spec

@@ -64,11 +64,6 @@ Patch4:         perl-5.10.0-libresolv.patch
 # patches ExtUtils-MakeMaker
 Patch5:         perl-USE_MM_LD_RUN_PATH.patch
 
-# Skip hostname tests, since hostname lookup isn't available in Fedora
-# buildroots by design.
-# patches Net::Config from libnet
-Patch6:         perl-disable_test_hosts.patch
-
 # The Fedora builders started randomly failing this futime test
 # only on x86_64, so we just don't run it. Works fine on normal
 # systems.
@@ -2026,7 +2021,6 @@ Perl extension for Version Objects
 %endif
 %patch4 -p1
 %patch5 -p1
-%patch6 -p1
 %patch7 -p1
 %patch8 -p1
 %patch15 -p1
@@ -4001,6 +3995,7 @@ popd
 - Sub-package Unicode-Collate (bug #1238760)
 - Sub-package Math-BigInt
 - Do not provide Net/libnet.cfg (bug #1238689)
+- Revert downstream change in Net::Config default configuration
 
 * Thu Jun 18 2015 Petr Pisar <ppisar@redhat.com> - 4:5.22.0-346
 - Subpackage "open" module in order to keep deprecated "encoding" module