Update umthes to v1.11.18

• fixes #18 (closed)
• optimizes static asset caching by setting appropriate http caching header
• reduce request logging

Reduce request logging

Should now produce:

method=GET path=/umthes/de/concepts/_00024495.html format=html controller=ConceptsController action=show status=200 allocations=110974 duration=602.56 view=231.59 db=92.41 time=2024-07-01 14:31:08 +0000 request_id=85caa159-e8b8-4021-98bf-11561207aafe params={"lang"=>"de", "id"=>"_00024495", "format"=>"html"}

# with cleaned stacktrace
method=GET path=/de/error.html format=html controller=UmtDashboardController action=error status=500 allocations=43472 duration=47.50 view=12.74 db=25.56 time=2024-07-01 15:54:29 +0200 request_id=3a446818-8886-4c71-a73e-170948b5e16f params={"lang"=>"de", "format"=>"html"} user_id=5 exception=["RuntimeError", "This is a test exception"] stacktrace=["app/controllers/umt_dashboard_controller.rb:105:in `error'"]

You can also set environment variable LOG_JSON = true to kick in json formatter.

If this works as expected, we ship compression, asset-caching and logging changes to further sns apps.