`workhorse:test using go 1.15` fails on master

Job #1460455704 failed for db32e7a9:

--- FAIL: TestAllowedGetGitArchive (1.08s)
    gitaly_integration_test.go:38: tcp://gitaly:8075
    gitaly_integration_test.go:191: 
        	Error Trace:	gitaly_integration_test.go:191
        	Error:      	Received unexpected error:
        	            	rpc error: code = Internal desc = CreateRepositoryFromURL: clone cmd wait: fatal: unable to access 'https://gitlab.com/gitlab-org/gitlab-test.git/': Failed to connect to gitlab.com port 443: Network is unreachable
        	            	: exit status 128
        	Test:       	TestAllowedGetGitArchive