calling closedconnection.close() should not throw exception.

src/main/java/com/zaxxer/hikari/pool/HikariPool.java

@@ -413,9 +413,9 @@ public class HikariPool extends PoolBase implements HikariPoolMXBean, IBagStateL
     */
    final void closeConnection(final PoolEntry poolEntry, final String closureReason)
    {
-      final Connection connection = poolEntry.connection;
-      poolEntry.close();
       if (connectionBag.remove(poolEntry)) {
+         final Connection connection = poolEntry.connection;
+         poolEntry.close();
          final int tc = totalConnections.decrementAndGet();
          if (tc < 0) {
             LOGGER.warn("{} - Internal accounting inconsistency, totalConnections={}", poolName, tc, new Exception());

src/main/java/com/zaxxer/hikari/pool/ProxyConnection.java

@@ -455,11 +455,14 @@ public abstract class ProxyConnection implements Connection
             public Object invoke(Object proxy, Method method, Object[] args) throws Throwable
             {
                final String methodName = method.getName();
-               if ("abort".equals(methodName)) { 
+               if ("isValid".equals(methodName)) {
+                  return Boolean.FALSE;
+               }
+               else if ("close".equals(methodName)) { 
                   return Void.TYPE;
                }
-               else if ("isValid".equals(methodName)) {
-                  return Boolean.FALSE;
+               else if ("abort".equals(methodName)) { 
+                  return Void.TYPE;
                }
                else if ("toString".equals(methodName)) {
                   return ClosedConnection.class.getCanonicalName();