multimedia/gstreamer1-plugins-rust: unbreak build on i386

fatal runtime error: Rust cannot catch foreign exceptions
thread '<unnamed>' panicked at '/wrkdirs/usr/ports/lang/rust/work/rustc-1.70.0-src/compiler/rustc_codegen_ssa/src/back/write.rs:1535:21: worker thread panicked', compiler/rustc_middle/src/util/bug.rs:36:26
(signal: 6, SIGABRT: process abort signal)

LLVM ERROR: out of memory
Allocation failed
error: could not compile gst-plugin-webrtc (lib)

Reported by: pkg-fallout