update healthcheck

Dockerfile

@@ -15,7 +15,7 @@ RUN \
     wget -qO- ${MONIT_URL}/monit-${MONIT_VERSION}.tar.gz | tar xz && \
     cd /opt/src/monit-${MONIT_VERSION} && \
     ./configure --prefix=${MONIT_HOME} --without-pam && \
-    make && make install && \
+    make -j1 && make install && \
     apk del gcc musl-dev make libressl-dev file zlib-dev && \
     rm -rf /var/cache/apk/* /opt/src