Use maxsize logrotate rule instead of size

The current ruleset means rotate the file daily unless the file grows
larger than 1Mb earlier, then rotate once the file reaches that size.

https://serverfault.com/questions/474941/how-to-rotate-log-based-on-an-interval-unless-log-exceeds-a-certain-size

src/logrotate.ejs

@@ -4,7 +4,7 @@
   rotate 7
   daily
   compress
-  size=1M
+  maxsize=1M
   missingok
   delaycompress
   copytruncate