Skip tests that needs an active internet connection

--- a/tests/libgit2/CMakeLists.txt
+++ b/tests/libgit2/CMakeLists.txt
@@ -66,10 +66,12 @@ endif()
 include(AddClarTest)
 add_clar_test(libgit2_tests offline             -v -xonline)
 add_clar_test(libgit2_tests invasive            -v -score::ftruncate -sfilter::stream::bigfile -sodb::largefiles -siterator::workdir::filesystem_gunk -srepo::init -srepo::init::at_filesystem_root)
-add_clar_test(libgit2_tests online              -v -sonline -xonline::customcert)
-add_clar_test(libgit2_tests online_customcert   -v -sonline::customcert)
-add_clar_test(libgit2_tests gitdaemon           -v -sonline::push)
-add_clar_test(libgit2_tests ssh                 -v -sonline::push -sonline::clone::ssh_cert -sonline::clone::ssh_with_paths -sonline::clone::path_whitespace_ssh)
-add_clar_test(libgit2_tests proxy               -v -sonline::clone::proxy)
-add_clar_test(libgit2_tests auth_clone          -v -sonline::clone::cred)
-add_clar_test(libgit2_tests auth_clone_and_push -v -sonline::clone::push -sonline::push)
+if(NOT DISABLE_ONLINE_TESTS)
+	add_clar_test(libgit2_tests online              -v -sonline -xonline::customcert)
+	add_clar_test(libgit2_tests online_customcert   -v -sonline::customcert)
+	add_clar_test(libgit2_tests gitdaemon           -v -sonline::push)
+	add_clar_test(libgit2_tests ssh                 -v -sonline::push -sonline::clone::ssh_cert -sonline::clone::ssh_with_paths -sonline::clone::path_whitespace_ssh)
+	add_clar_test(libgit2_tests proxy               -v -sonline::clone::proxy)
+	add_clar_test(libgit2_tests auth_clone          -v -sonline::clone::cred)
+	add_clar_test(libgit2_tests auth_clone_and_push -v -sonline::clone::push -sonline::push)
+endif()