Revert "[PLT-7475] Add S3 region to system console and add S3 validation (#7373)" (#7387)

This reverts commit 8d680cf64e.

Move to 4.3.
Will discuss more if validation is necessary.

model/config.go

@@ -88,9 +88,6 @@ const (
 
 	SQL_SETTINGS_DEFAULT_DATA_SOURCE = "mmuser:mostest@tcp(dockerhost:3306)/mattermost_test?charset=utf8mb4,utf8&readTimeout=30s&writeTimeout=30s"
 
-	FILE_SETTINGS_DEFAULT_AMAZON_S3_ENDPOINT = "s3.amazonaws.com"
-	FILE_SETTINGS_DEFAULT_AMAZON_S3_REGION   = "us-east-1"
-
 	EMAIL_SETTINGS_DEFAULT_FEEDBACK_ORGANIZATION = ""
 
 	SUPPORT_SETTINGS_DEFAULT_TERMS_OF_SERVICE_LINK      = "https://about.mattermost.com/default-terms/"
@@ -271,9 +268,9 @@ type FileSettings struct {
 	InitialFont             string
 	AmazonS3AccessKeyId     string
 	AmazonS3SecretAccessKey string
-	AmazonS3Bucket          *string
-	AmazonS3Region          *string
-	AmazonS3Endpoint        *string
+	AmazonS3Bucket          string
+	AmazonS3Region          string
+	AmazonS3Endpoint        string
 	AmazonS3SSL             *bool
 	AmazonS3SignV2          *bool
 	AmazonS3SSE             *bool
@@ -601,19 +598,9 @@ func (o *Config) SetDefaults() {
 		*o.FileSettings.DriverName = IMAGE_DRIVER_LOCAL
 	}
 
-	if o.FileSettings.AmazonS3Bucket == nil {
-		o.FileSettings.AmazonS3Bucket = new(string)
-		*o.FileSettings.AmazonS3Bucket = ""
-	}
-
-	if o.FileSettings.AmazonS3Region == nil {
-		o.FileSettings.AmazonS3Region = new(string)
-		*o.FileSettings.AmazonS3Region = FILE_SETTINGS_DEFAULT_AMAZON_S3_REGION
-	}
-
-	if o.FileSettings.AmazonS3Endpoint == nil {
-		o.FileSettings.AmazonS3Endpoint = new(string)
-		*o.FileSettings.AmazonS3Endpoint = FILE_SETTINGS_DEFAULT_AMAZON_S3_ENDPOINT
+	if o.FileSettings.AmazonS3Endpoint == "" {
+		// Defaults to "s3.amazonaws.com"
+		o.FileSettings.AmazonS3Endpoint = "s3.amazonaws.com"
 	}
 
 	if o.FileSettings.AmazonS3SSL == nil {