Let Loki start when using the debug image. (#1372)

Signed-off-by: Cyril Tovena <cyril.tovena@gmail.com>

cmd/loki/Dockerfile.debug

@@ -24,5 +24,5 @@ RUN apk add --no-cache libc6-compat
 # Run delve, ending with -- because we pass params via kubernetes, per the docs:
 #   Pass flags to the program you are debugging using --, for example:`
 #   dlv exec ./hello -- server --config conf/config.toml`
-ENTRYPOINT ["/usr/bin/dlv", "--listen=:40000", "--headless=true", "--api-version=2", "exec", "/usr/bin/loki-debug", "--"]
+ENTRYPOINT ["/usr/bin/dlv", "--listen=:40000", "--headless=true", "--log", "--continue" , "--api-version=2", "exec", "/usr/bin/loki-debug", "--"]
 CMD        ["-config.file=/etc/loki/local-config.yaml"]