Wrap zip step into run_silent in compile.sh

Ordering of message were confusing if the zip step was failing.

Fixes #319

--
MOS_MIGRATED_REVID=98932569
diff --git a/scripts/bootstrap/compile.sh b/scripts/bootstrap/compile.sh
index 7af066f..956463f 100755
--- a/scripts/bootstrap/compile.sh
+++ b/scripts/bootstrap/compile.sh
@@ -306,7 +306,7 @@
 (cd ${OUTPUT_DIR}/ ; cat client ${TO_ZIP} | ${MD5SUM} | awk '{ print $1; }' > install_base_key)
 (cd ${OUTPUT_DIR}/ ; echo "${JAVA_VERSION}" > java.version)
 (cd ${OUTPUT_DIR}/ ; find . -type f | xargs -P 10 touch -t 198001010000)
-(cd ${OUTPUT_DIR}/ ; zip $ZIPOPTS -q package.zip ${TO_ZIP} install_base_key java.version)
+(cd ${OUTPUT_DIR}/ ; run_silent zip $ZIPOPTS -q package.zip ${TO_ZIP} install_base_key java.version)
 cat ${OUTPUT_DIR}/client ${OUTPUT_DIR}/package.zip > ${OUTPUT_DIR}/bazel
 zip -qA ${OUTPUT_DIR}/bazel \
   || echo "(Non-critical error, ignore.)"