Fix flaky unit tests caused by randomly generated dotComID

Author: crazytonyli

WordPress/Classes/Models/Blog.h

@@ -121,6 +121,7 @@ typedef NS_ENUM(NSInteger, SiteVisibility) {
 @interface Blog : NSManagedObject
 
 @property (nonatomic, strong, readwrite, nullable) NSNumber *blogID __deprecated_msg("Use dotComID instead");
+/// WordPress.com site ID stored as signed 32-bit integer.
 @property (nonatomic, strong, readwrite, nullable) NSNumber *dotComID;
 @property (nonatomic, strong, readwrite, nullable) NSString *xmlrpc;
 @property (nonatomic, strong, readwrite, nullable) NSString *apiKey;

WordPress/WordPressTest/BlogBuilder.swift

@@ -17,7 +17,7 @@ final class BlogBuilder {
         blog = NSEntityDescription.insertNewObject(forEntityName: Blog.entityName(), into: context) as! Blog
 
         // Non-null properties in Core Data
-        blog.dotComID = NSNumber(value: arc4random_uniform(UInt32.max))
+        blog.dotComID = NSNumber(value: arc4random_uniform(999_999))
         blog.url = "https://\(blog.dotComID!).example.com"
         blog.xmlrpc = "https://\(blog.dotComID!).example.com/xmlrpc.php"
     }