Fix for gitextractor proxy config

git.ProxyTypeSpecified should be used when specifying proxy address,
otherwise git seems to only use http_proxy configuration from
environment variables even when a proxy url has been given.

backend/plugins/gitextractor/parser/clone.go

@@ -59,7 +59,7 @@ func (l *GitRepoCreator) CloneOverHTTP(repoId, url, user, password, proxy string
 	return withTempDirectory(func(dir string) (*GitRepo, error) {
 		cloneOptions := &git.CloneOptions{Bare: true}
 		if proxy != "" {
-			cloneOptions.FetchOptions.ProxyOptions.Type = git.ProxyTypeAuto
+			cloneOptions.FetchOptions.ProxyOptions.Type = git.ProxyTypeSpecified
 			cloneOptions.FetchOptions.ProxyOptions.Url = proxy
 		}
 		if user != "" {