Use modern alpine

Your version of alpine is two years out of date and has some security and library problems. This replaces 3.11 with 3.15 I did not independently test this change because I don't actually know how
2 years ago · 2459d58563
parent 8e9f665590
commit 2459d58563
1 changed files with 1 additions and 1 deletions
--- a/mix/Dockerfile
+++ b/mix/Dockerfile
@ -1,4 +1,4 @@
-FROM alpine:3.11
+FROM alpine:3.15
 LABEL maintainer="ProcessOne <contact@process-one.net>" \
      product="Ejabberd mix development environment"