HTTP: fix extraction of filename #2821

Job	Run time
Python Bindings (ubuntu-latest)	1m 20s
ubuntu-latest x86_64 --with-local-libgcrypt cc	6m 21s
ubuntu-latest x86_64 cc	7m 49s
ubuntu-20.04 x86_64 --with-local-libgcrypt cc	6m 0s
ubuntu-20.04 x86_64 cc	6m 7s
macOS-latest x86_64 --with-local-libgcrypt cc	4m 54s
macOS-latest x86_64 cc	5m 27s
macos-11 x86_64 --with-local-libgcrypt cc	5m 22s
macos-11 x86_64 cc	5m 35s
windows-latest x86_64 --with-local-libgcrypt cc	19m 19s
windows-latest x86_64 cc	10m 57s
ubuntu-20.04 x86_64 gcc-7 --with-pcre --with-maxminddb --with-sanitizer	9m 47s
ubuntu-22.04 x86_64 gcc-12 --with-pcre --with-maxminddb --with-sanitizer --with-lto-and-gold-linker	10m 11s
ubuntu-20.04 x86_64 clang-7 --with-pcre --with-maxminddb --with-sanitizer	12m 5s
ubuntu-22.04 x86_64 clang-14 --with-pcre --with-maxminddb --with-sanitizer --with-lto-and-gold-linker	11m 38s
ubuntu-latest x86_64 cc --with-pcre --with-maxminddb --with-thread-sanitizer	20m 17s
ubuntu-latest x86_64 cc --with-pcre --with-maxminddb --with-sanitizer nBPF	6m 40s
ubuntu-22.04 x86_64 clang-14 --with-pcre --with-maxminddb --with-memory-sanitizer	16m 25s
macOS-latest x86_64 cc --with-pcre --with-maxminddb	4m 55s
macos-12 x86_64 cc --with-pcre --with-maxminddb	5m 2s
ubuntu-latest arm64 cc --with-pcre --with-maxminddb	20m 14s
ubuntu-latest armhf cc --with-pcre --with-maxminddb --with-sanitizer	37m 53s
ubuntu-latest s390x cc --with-pcre --with-maxminddb	18m 18s
Test Utils (ubuntu-latest)	2m 21s
	4h 14m 57s

Provide feedback