Also check for empty content length

[rullzer]

My guess it this is caused by php 7.2

I was debugging the client with the https://github.com/nextcloud/end_to_end_encryption app. To encrypt a folder a PUT request is send to

<server>/ocs/v2.php/apps/end_to_end_encryption/api/v1/encrypted/<fileid>

Without this patch this will fail. Because we don't correctly get the id from the urlparameters.

[codecov]

Codecov Report

Merging #7523 into master will decrease coverage by <.01%.
The diff coverage is 100%.

@@ Coverage Diff @@## master #7523 +/- ##
============================================
- Coverage 51.16% 51.16% -0.01% - Complexity 24865 24866 +1 
============================================
Files 1601 1601 Lines 94683 94684 +1 Branches 1368 1368 ============================================
- Hits 48446 48443 -3 - Misses 46237 46241 +4

Impacted Files	Coverage Δ	Complexity Δ
lib/private/AppFramework/Http/Request.php	92.7% <100%> (+0.02%)	149 <0> (+1)	⬆️
core/js/js.js	62.98% <0%> (-0.57%)	0% <0%> (ø)
apps/files_trashbin/lib/Trashbin.php	72.53% <0%> (+0.24%)	136% <0%> (ø)	⬇️