Update Rust host compilation command in Dockerfile

Dockerfile

@@ -5,6 +5,7 @@ FROM ghcr.io/openwrt/sdk:${SAFE_TARGET}-${VERSION}
 
 RUN ./scripts/feeds update packages && \
     make defconfig && \
-    make package/feeds/packages/rust/host-compile -j$(nproc) && \
+    { make package/feeds/packages/rust/host-compile -j$(nproc) || \
+      make package/feeds/packages/rust/host-compile -j1 V=sc; } && \
     rm -rf build_dir/host/rustc-*/rustc-*/build \
            dl/rustc-*.tar.*