[9.18] chg: test: Bump max-recursion-queries to 100 in resolver system test
With max-recursion-queries set to 50 the resolver system test was unstable in the "checking query resolution for a domain with a valid glueless delegation chain" check as ns1 replied with SERVFAIL.
Closes #4897 (closed)
Backport of MR !9435 (merged)