Revert "Relax error message check for OpenSSL 3.1"

This reverts commit fc4629d.

The test case "test_connect_certificate_verify_failed_exception_message"
does want to check the reason behind a certificate verification failure
to be included in the exception message.

test/openssl/test_ssl.rb

@@ -1046,7 +1046,9 @@ def test_connect_certificate_verify_failed_exception_message
     start_server(ignore_listener_error: true) { |port|
       ctx = OpenSSL::SSL::SSLContext.new
       ctx.set_params
-      assert_raise_with_message(OpenSSL::SSL::SSLError, /certificate/) {
+      # OpenSSL <= 1.1.0: "self signed certificate in certificate chain"
+      # OpenSSL >= 3.0.0: "self-signed certificate in certificate chain"
+      assert_raise_with_message(OpenSSL::SSL::SSLError, /self.signed/) {
         server_connect(port, ctx)
       }
     }