Steps to reproduce:
1. Open process instance variable tab with pagination displayed (the size of pagination might need to be decreased in order to do that)
2. Change page for some bigger number like 11 or something.
3. Select some activity in diagram that will result in decrease of total pages count.

Actual:
1. Url is changed 2 times.
2. Two request are made

Expected:
1. Url changes only ones or second change replace previous one
2. Request is made only ones.

Hint: this bug might be observed on other pages with pagination.
Hint: Possible solution would be to change page to 1 after selecting activity on diagram, so that pagination will not change (there is always first page).