Update entrypoint.sh to use $THREADS for parallel compilation on start if present (#673)

entrypoint.sh

@@ -5,7 +5,7 @@ cd /build
 
 if [ "$REBUILD" != "false" ]; then
 	rm -rf ./local-ai
-	ESPEAK_DATA=/build/lib/Linux-$(uname -m)/piper_phonemize/lib/espeak-ng-data make build
+	ESPEAK_DATA=/build/lib/Linux-$(uname -m)/piper_phonemize/lib/espeak-ng-data make build -j${THREADS:-1}
 fi
 
-./local-ai "$@"
+./local-ai "$@"