allow for SSLContext#dup to work (copy-ing Ruby level i-variables only)

Author: kares

src/main/java/org/jruby/ext/openssl/SSLContext.java

@@ -181,7 +181,6 @@ public static void createSSLContext(final Ruby runtime, final RubyModule SSL) {
         SSLContext.defineAlias("ssl_timeout=", "timeout=");
 
         SSLContext.defineAnnotatedMethods(SSLContext.class);
-        SSLContext.undefineMethod("dup");
 
         final Set<String> methodKeys = SSL_VERSION_OSSL2JSSE.keySet();
         final RubyArray methods = runtime.newArray( methodKeys.size() );
@@ -292,6 +291,15 @@ public IRubyObject initialize(IRubyObject[] args) {
         return initializeImpl();
     }
 
+    @Override
+    public IRubyObject initialize_copy(IRubyObject original) {
+        return super.initialize_copy(original);
+        // NOTE: only instance variables (no internal state) on #dup
+        // final SSLContext that = (SSLContext) original;
+        // this.ciphers = that.ciphers;
+        // return this;
+    }
+
     final SSLContext initializeImpl() { return this; }
 
     @JRubyMethod