Bump runtime debian

From `stretch-20190708-slim` to `stretch-20190812-slim`

Signed-off-by: Ulysses Souza <[email protected]>

Dockerfile

@@ -3,7 +3,7 @@ ARG PYTHON_VERSION=3.7.4
 ARG BUILD_ALPINE_VERSION=3.10
 ARG BUILD_DEBIAN_VERSION=slim-stretch
 ARG RUNTIME_ALPINE_VERSION=3.10.1
-ARG RUNTIME_DEBIAN_VERSION=stretch-20190708-slim
+ARG RUNTIME_DEBIAN_VERSION=stretch-20190812-slim
 
 ARG BUILD_PLATFORM=alpine