[Go] use EqualFold instead instead of comparing strings in lower case

modules/openapi-generator/src/main/resources/go/client.mustache

@@ -111,7 +111,7 @@ func selectHeaderAccept(accepts []string) string {
 // contains is a case insensitive match, finding needle in a haystack
 func contains(haystack []string, needle string) bool {
 	for _, a := range haystack {
-		if strings.ToLower(a) == strings.ToLower(needle) {
+		if strings.EqualFold(a, needle) {
 			return true
 		}
 	}

modules/openapi-generator/src/main/resources/go/signing.mustache

@@ -136,7 +136,7 @@ func (h *HttpSignatureAuth) ContextWithValue(ctx context.Context) (context.Conte
 	}
 	m := make(map[string]bool)
 	for _, h := range h.SignedHeaders {
-		if strings.ToLower(h) == strings.ToLower(HttpHeaderAuthorization) {
+		if strings.EqualFold(h, HttpHeaderAuthorization) {
 			return nil, fmt.Errorf("Signed headers cannot include the 'Authorization' header")
 		}
 		m[h] = true