Expose RequestBuilderBase setInetAddress and setLocalnetAddress.

Example:
var bindTo = InetAddress.getByName("192.168.1.1")
httpConfig.localAddress(bindTo)

[backport of https://github.com/excilys/gatling/issues/1278 from 2.0.0]
PR fixes: whitespace/formatting corrections

Tabs > spaces.
Merge pull request #1985 from SkySchulz/setLocal-backport

HTTP: Expose RequestBuilderBase setInetAddress and setLocalnetAddress.