Tags, View My Threads, and pagination

Found a couple of minor bugs.

With a tag in use, the View My Threads filter fails to update pagination;

• First I went to Bug Reports. (Everything's fine so far.)
• Then I clicked on Website. (Pagination shows 6 pages.)
• Then I used the View My Threads filter. (Still 6 pages.)

So then I decided to try switching things around.

Using a tag will disable the View My Threads filter if it's active;

• First I went to Bug Reports. (Everything's fine so far.)
• Then I clicked on View My Threads. (Still fine atm.)
• Then I clicked on Website. (View My Posts disabled.)

This was on Firefox Quantum 63.0 x64 on Ubuntu 18.10.