fix(web): OAuth quota size (#18526)

fix(server): oauth quota size

server/src/dtos/system-config.dto.ts

@@ -360,7 +360,9 @@ class SystemConfigOAuthDto {
 
   @IsNumber()
   @Min(0)
-  defaultStorageQuota!: number;
+  @Optional({ nullable: true })
+  @ApiProperty({ type: 'integer', format: 'int64' })
+  defaultStorageQuota!: number | null;
 
   @ValidateBoolean()
   enabled!: boolean;