fix(container): update image caddy to v2.7.6 (#19)

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This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| caddy | final | patch | `2.7.5-alpine` -> `2.7.6-alpine` |

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Dockerfile

@@ -46,7 +46,7 @@ RUN wget "$OVERMIND_URL" && gunzip ${OVERMIND_FILE} && chmod +x "$OVERMIND"
 #
 # Fly app
 #
-FROM caddy:2.7.5-alpine
+FROM caddy:2.7.6-alpine
 
 ARG SUPERCRONIC
 ARG OVERMIND