🐛 bug: fix constraints when to use multiple params

[efectn]

Description

Fix route patterns like:

• /:lang<len(2)>/videos/:page<range(1,1000)>/
• /:lang/videos/:page<range(1,1000)>/
• /:lang<len(2)>/videos/:page/

Fixes #2076

Type of change

• Bug fix (non-breaking change which fixes an issue)

Checklist:

• I have performed a self-review of my own code
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• I tried to make my code as fast as possible with as few allocations as possible
• For new code I have written benchmarks so that they can be analyzed and improved