v1.7.6: revert googlevideo.com SNI rewrite (#275, #281)

v1.7.4 added googlevideo.com to SNI_REWRITE_SUFFIXES on the theory
that video chunks should bypass the Apps Script relay. Multiple
users (#275 amirabbas117, #281 mrerf) reported total YouTube
breakage on v1.7.4: SNI-rewriting googlevideo.com:443 to a GFE IP
returned TLS handshake failure / wrong-cert error.

Root cause: googlevideo.com is served by Google's separate "EVA"
edge IPs, not the regular GFE IPs that the user's `google_ip`
typically points at. The SNI-rewrite tunnel TLS handshake against
a GFE IP for googlevideo.com SNI fails because the GFE IP doesn't
hold a googlevideo.com cert.

Pre-v1.7.4 behaviour restored: video chunks fall through to the
Apps Script relay path. Slower but reliable on every GFE IP.

The other v1.7.4 youtube_via_relay carve-out fixes (ytimg.com
correctly stays on SNI rewrite, youtubei.googleapis.com correctly
goes through relay) remain intact — those were a separate
improvement and still correct.

Future: if we want direct googlevideo.com routing, it needs a
separate `eva_edge_ip` config knob — users can populate from their
own EVA scan, defaulting to "use relay" if not configured.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "mhrv-rs"
-version = "1.7.5"
+version = "1.7.6"
 edition = "2021"
 description = "Rust port of MasterHttpRelayVPN -- DPI bypass via Google Apps Script relay with domain fronting"
 license = "MIT"