Merge branch 'release-config-import' into 'develop'

Import release config from env variable or /etc/pleroma/config.exs and warn if the file is missing

See merge request pleroma/pleroma!1269

config/releases.exs

@@ -1 +1,16 @@
 import Config
+
+config_path = System.get_env("PLEROMA_CONFIG_PATH") || "/etc/pleroma/config.exs"
+
+if File.exists?(config_path) do
+  import_config config_path
+else
+  warning = [
+    IO.ANSI.red(),
+    IO.ANSI.bright(),
+    "!!! #{config_path} not found! Please ensure it exists and that PLEROMA_CONFIG_PATH is unset or points to an existing file",
+    IO.ANSI.reset()
+  ]
+
+  IO.puts(warning)
+end