free native WOLFSSL when WolfSSLSocket is closed, earlier than finalize

src/java/com/wolfssl/provider/jsse/WolfSSLSocket.java

@@ -1371,6 +1371,12 @@ public class WolfSSLSocket extends SSLSocket {
 
                 synchronized (handshakeLock) {
                     this.connectionClosed = true;
+
+                    /* Connection is closed, free native WOLFSSL session
+                     * to release native memory earlier than garbage collector
+                     * might with finalize(). */
+                    this.ssl.freeSSL();
+                    this.ssl = null;
                 }
             }
 
@@ -1396,6 +1402,8 @@ public class WolfSSLSocket extends SSLSocket {
 
         } catch (IllegalStateException e) {
             throw new IOException(e);
+        } catch (WolfSSLJNIException jnie) {
+            throw new IOException(jnie);
         }
     }