Add detailed message for msttcorefonts failed to download

This is workaround of https://bugs.launchpad.net/ubuntu/+source/msttcorefonts/+bug/1465721

Dockerfile

@@ -49,7 +49,8 @@ RUN echo "#!/bin/sh\nexit 0" > /usr/sbin/policy-rc.d && \
         ttf-mscorefonts-installer \
         xvfb \
         zlib1g && \
-    [  $(ls -l /usr/share/fonts/truetype/msttcorefonts | wc -l) -eq 61 ] && \
+    if [  $(ls -l /usr/share/fonts/truetype/msttcorefonts | wc -l) -ne 61 ]; \
+        then echo 'msttcorefonts failed to download'; exit 1; fi  && \
     sudo -u postgres psql -c "CREATE DATABASE onlyoffice;" && \
     sudo -u postgres psql -c "CREATE USER onlyoffice WITH password 'onlyoffice';" && \
     sudo -u postgres psql -c "GRANT ALL privileges ON DATABASE onlyoffice TO onlyoffice;" && \