Tests: Account for non-numeric strings in tests for get_space_allowed().

Provides a specific test for a case where a non-numeric strings are assigned to `blog_upload_space` at both the site and network levels.

See #34037.


git-svn-id: https://develop.svn.wordpress.org/trunk@34900 602fd350-edb4-49c9-b593-d223f7449a82

tests/phpunit/tests/multisite/getSpaceAllowed.php

@@ -92,6 +92,7 @@ class Tests_Multisite_Get_Space_Allowed extends WP_UnitTestCase {
 
 			// If neither network or site options are valid, fallback to the default.
 			array( false, false, 100 ),
+			array( 'NAN', 'NAN', 100 ),
 
 			// These are likely unexpected.
 			array( 0,     666,   100 ),