Pass --global when calling git config --get, for consistency with…

… `git config --set` (go-gitea#23157)

This arose out of go-gitea#22451; it seems we are checking using non-global
settings to see if a config value is set, in order to decide whether to
call another global(-indeed) configuration command. This PR changes it
so that both the check and the set are for global configuration.

modules/git/git.go

@@ -313,7 +313,7 @@ func CheckGitVersionAtLeast(atLeast string) error {
 }
 
 func configSet(key, value string) error {
-	stdout, _, err := NewCommand(DefaultContext, "config", "--get").AddDynamicArguments(key).RunStdString(nil)
+	stdout, _, err := NewCommand(DefaultContext, "config", "--global", "--get").AddDynamicArguments(key).RunStdString(nil)
 	if err != nil && !err.IsExitCode(1) {
 		return fmt.Errorf("failed to get git config %s, err: %w", key, err)
 	}
@@ -332,7 +332,7 @@ func configSet(key, value string) error {
 }
 
 func configSetNonExist(key, value string) error {
-	_, _, err := NewCommand(DefaultContext, "config", "--get").AddDynamicArguments(key).RunStdString(nil)
+	_, _, err := NewCommand(DefaultContext, "config", "--global", "--get").AddDynamicArguments(key).RunStdString(nil)
 	if err == nil {
 		// already exist
 		return nil
@@ -350,7 +350,7 @@ func configSetNonExist(key, value string) error {
 }
 
 func configAddNonExist(key, value string) error {
-	_, _, err := NewCommand(DefaultContext, "config", "--get").AddDynamicArguments(key, regexp.QuoteMeta(value)).RunStdString(nil)
+	_, _, err := NewCommand(DefaultContext, "config", "--global", "--get").AddDynamicArguments(key, regexp.QuoteMeta(value)).RunStdString(nil)
 	if err == nil {
 		// already exist
 		return nil
@@ -367,7 +367,7 @@ func configAddNonExist(key, value string) error {
 }
 
 func configUnsetAll(key, value string) error {
-	_, _, err := NewCommand(DefaultContext, "config", "--get").AddDynamicArguments(key).RunStdString(nil)
+	_, _, err := NewCommand(DefaultContext, "config", "--global", "--get").AddDynamicArguments(key).RunStdString(nil)
 	if err == nil {
 		// exist, need to remove
 		_, _, err = NewCommand(DefaultContext, "config", "--global", "--unset-all").AddDynamicArguments(key, regexp.QuoteMeta(value)).RunStdString(nil)