[ruby/net-http] Use omit instead of skip for test-unit

https://github.com/ruby/net-http/commit/843d4548de

test/net/http/test_https.rb

@@ -137,7 +137,7 @@ class TestNetHTTPS < Test::Unit::TestCase
   def test_session_reuse
     # FIXME: The new_session_cb is known broken for clients in OpenSSL 1.1.0h.
     # See https://github.com/openssl/openssl/pull/5967 for details.
-    skip if OpenSSL::OPENSSL_LIBRARY_VERSION =~ /OpenSSL 1.1.0h/
+    omit if OpenSSL::OPENSSL_LIBRARY_VERSION =~ /OpenSSL 1.1.0h/
 
     http = Net::HTTP.new(HOST, config("port"))
     http.use_ssl = true
@@ -164,7 +164,7 @@ class TestNetHTTPS < Test::Unit::TestCase
 
   def test_session_reuse_but_expire
     # FIXME: The new_session_cb is known broken for clients in OpenSSL 1.1.0h.
-    skip if OpenSSL::OPENSSL_LIBRARY_VERSION =~ /OpenSSL 1.1.0h/
+    omit if OpenSSL::OPENSSL_LIBRARY_VERSION =~ /OpenSSL 1.1.0h/
 
     http = Net::HTTP.new(HOST, config("port"))
     http.use_ssl = true

test/net/http/test_https_proxy.rb

@@ -10,7 +10,7 @@ class HTTPSProxyTest < Test::Unit::TestCase
     begin
       OpenSSL
     rescue LoadError
-      skip 'autoload problem. see [ruby-dev:45021][Bug #5786]'
+      omit 'autoload problem. see [ruby-dev:45021][Bug #5786]'
     end
 
     TCPServer.open("127.0.0.1", 0) {|serv|