Attempt to bound how long a connection.close() call can take to 30 seconds on JDBC41 drivers.

hikaricp-common/src/main/java/com/zaxxer/hikari/util/PoolUtilities.java

@@ -40,8 +40,14 @@ public final class PoolUtilities
    public void quietlyCloseConnection(final Connection connection)
    {
       if (connection != null) {
+         try {
             try {
                setNetworkTimeout(executorService, connection, TimeUnit.SECONDS.toMillis(30), true);
+            }
+            catch (SQLException e) {
+               // keep going, close anyway
+            }
+
             connection.close();
          }
          catch (Exception e) {