Flipp: remove IP as a bidder request parameter

[hasan-kanjee]

Based on the discussion here prebid/prebid.github.io#4551 (comment), we are removing ip as a bidder request parameter. IP will be retrieved from request.Device.IP.

[github-actions]

Code coverage summary

Note:

• Prebid team doesn't anticipate tests covering code paths that might result in marshal and unmarshal errors
• Coverage summary encompasses all commits leading up to the latest one, 48710ca

flipp

Refer here for heat map coverage report

github.com/prebid/prebid-server/adapters/flipp/flipp.go:36:	Builder			100.0%
github.com/prebid/prebid-server/adapters/flipp/flipp.go:43:	MakeRequests		100.0%
github.com/prebid/prebid-server/adapters/flipp/flipp.go:61:	makeRequest		75.0%
github.com/prebid/prebid-server/adapters/flipp/flipp.go:80:	processImp		80.0%
github.com/prebid/prebid-server/adapters/flipp/flipp.go:156:	buildPrebidRequest	100.0%
github.com/prebid/prebid-server/adapters/flipp/flipp.go:173:	MakeBids		93.3%
github.com/prebid/prebid-server/adapters/flipp/flipp.go:203:	getAdTypes		100.0%
github.com/prebid/prebid-server/adapters/flipp/flipp.go:210:	buildBid		100.0%
total:								(statements)		88.5%