Level1 nav bar do not works with case insensitive urls

**Operating System**: Windows

**DocFX Version Used**: 2.58.2

**Template used**: default

**Steps to Reproduce**:

1. Try open in browser html with diff case. For example /doc/Tutorial.html instead of /doc/tutorial.html

**Expected Behavior**: IIS can handle it level1 bar path should be rendered

**Actual Behavior**: level1 nav bar do not render path