Inconsistencies with ES output plugin

[ctindel]

In 6.0.1 you are able to include the https:// in the hosts field of the elasticsearch input but if you do the same on the hosts field of the elasticsearch input plugin you get a very cryptic error message.

Since these are all related to pieces of our stack it seems like there should be absolute consistency between the way options are presented in the pipeline configuration files between the es input, filter, and output plugins.