Doesn't count spaces as difference between search terms

[pingram3541]

Describe the bug
When searching for a url that has a trailing space after the domain, so as to replace it with a valid url that does not have a trailing space, it sees the search term as not being any different from the replace term.

To Reproduce
Steps to reproduce the behavior:

1. Create a post and insert an image and then invalidate the url by adding a space after .com
   i.e //mysite.com /wp-content/media/....
2. Go to 'Search & Replace'
3. Click on 'Search for'
4. Type in: '//mysite.com /'
5. Click on 'Replace with'
6. Type in: '//mysite.com/'
7. Select (prefix)_posts table.
8. Perform dry run

Expected behavior
Correctly determine urls w/ space do not match urls without space (i.e. %20%).