uhttpd: update to Git HEAD (2025-07-06)

uhttpd: update to Git HEAD (2025-07-06)

b3e3c05 client: don't send stray EOF chunk on connection timeout
fad0d05 proc: inhibit chunked transfer encoding on existing TEs or known length
3d6f01b file: prevent writes beyond end of uh_buf on enumerating directories
c7294e7 client: reject requests with multiple content-lengths and/or TEs
7e64e8b client: Allow sending content in DONE state

uhttpd commit 3d6f01b fixes: CVE-2025-32108

Link: https://github.com/openwrt/openwrt/pull/19290
(cherry picked from commit efb4200ba569d6ff79ec58a3c44cd8769ba40fdc)
Link: https://github.com/openwrt/openwrt/pull/19563
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>