Add test case for incorrect IRI-encoding of GET URLs

This is follow up for #207 (closed). I simulate using sample URI mentioned on existing IRI test case, and the result is:

Missing expected file .test_10167/?p=autoconf-archive.git;a=blob_plain;f=m4/ax_cxx_compile_stdcxx.html [--iri -e robots=on --trust-server-names --local-encoding=utf-8 --restrict-file-names=nocontrol -nH -r]

When I debug, it produce file: "index.html?p=autoconf-archive.git;a=blob_plain;f=m4%2Fax_cxx_compile_stdcxx.html".
What could be wrong?