bug 2628: fixing test script to deal with DESTDIR in Makefile.PL

Recently, there were changes to the Makefile.PL to make it install in a
DESTDIR that the OS (debian) may choose. This broke the test suite.
Since we're not installing the stuff in the t/ directory, we need to
ignore the DESTDIR specifiation before we write the test-config.txt.
So, this patch adds a call to the _strip_destdir function for all
directories written to the t/test-config.txt file.

Signed-off-by: Galen Charlton <galen.charlton@liblime.com>

Makefile.PL

@@ -1587,7 +1587,7 @@ sub postamble {
 
             # these directories will be relocated to the 't' directory
             foreach my $dirname ( keys %$target_directories ) {
-                my $dir = $target_directories->{$dirname};
+                my $dir = main::_strip_destdir( $target_directories->{$dirname} );
                 if ( exists $test_suite_override_dirs{$dirname} ) {
                     $dir = main::get_test_dir($dirname);
                 }