configs: use local set of go-getter detectors

In an earlier change we switched to defining our own sets of detectors,
getters, etc for go-getter in order to insulate us from upstream changes
to those sets that might otherwise change the user-visible behavior of
Terraform's module installer.

However, we apparently neglected to actually refer to our local set of
detectors, and continued to refer to the upstream set. Here we catch up
with the latest detectors from upstream (taken from the version of
go-getter we currently have vendored) and start using that fixed set.

Currently we are maintaining these custom go-getter sets in two places
due to the configload vs. initwd distinction. That was already true for
goGetterGetters and goGetterDecompressors, and so I've preserved that for
now just to keep this change relatively simple; in later change it would
be nice to factor these "get with go getter" functions out into a shared
location which we can call from both configload and initwd.

configs/configload/getter.go

@@ -19,6 +19,7 @@ import (
 
 var goGetterDetectors = []getter.Detector{
 	new(getter.GitHubDetector),
+	new(getter.GitDetector),
 	new(getter.BitBucketDetector),
 	new(getter.GCSDetector),
 	new(getter.S3Detector),
@@ -84,7 +85,7 @@ func (g reusingGetter) getWithGoGetter(instPath, addr string) (string, error) {
 
 	log.Printf("[DEBUG] will download %q to %s", packageAddr, instPath)
 
-	realAddr, err := getter.Detect(packageAddr, instPath, getter.Detectors)
+	realAddr, err := getter.Detect(packageAddr, instPath, goGetterDetectors)
 	if err != nil {
 		return "", err
 	}

internal/initwd/getter.go

@@ -21,6 +21,7 @@ import (
 
 var goGetterDetectors = []getter.Detector{
 	new(getter.GitHubDetector),
+	new(getter.GitDetector),
 	new(getter.BitBucketDetector),
 	new(getter.GCSDetector),
 	new(getter.S3Detector),
@@ -86,7 +87,7 @@ func (g reusingGetter) getWithGoGetter(instPath, addr string) (string, error) {
 
 	log.Printf("[DEBUG] will download %q to %s", packageAddr, instPath)
 
-	realAddr, err := getter.Detect(packageAddr, instPath, getter.Detectors)
+	realAddr, err := getter.Detect(packageAddr, instPath, goGetterDetectors)
 	if err != nil {
 		return "", err
 	}