Error msg so obscure when connect url port miss

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Hi, the problem takes me some time:
when I init InfluxDB instance from `InfluxDBFactory.connect`, I miss a port, like:
~~~java
InfluxDBFactory.connect("127.0.0.1", "username", "password");
~~~
actually, the code should be
~~~java
InfluxDBFactory.connect("127.0.0.1:8086", "username", "password");
~~~
but I didn't notice it. then I query a table, the program throw exception and show stack trace:
~~~java
Exception in thread "main" org.influxdb.InfluxDBException:
at org.influxdb.InfluxDBException.buildExceptionForErrorState(InfluxDBException.java:175)
at org.influxdb.impl.InfluxDBImpl.execute(InfluxDBImpl.java:837)
at org.influxdb.impl.InfluxDBImpl.executeQuery(InfluxDBImpl.java:824)
at org.influxdb.impl.InfluxDBImpl.query(InfluxDBImpl.java:559)
~~~
I think its so obscure, the exception can throw early. For example, when init InfluxDB instance, it can throw `IllegalArugemntException: The port cannot be null`

Start at InfluxDBFactory.connect, then trace the connection setup before the query path shown through InfluxDBImpl.execute and executeQuery. Reproduce the missing-port example and make the failure occur during initialization with a clear exception; the existing query path should no longer produce an obscure empty InfluxDBException.

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