fix(deps) install wget as well (#287)

With FIPS build, we are dropping luasec in the container(on both FIPS
and non-FIPS build), as it's only used in development; it's now moved
to a dev dependency
(Kong/kong-ee@d0c789d).

With that removed, luarocks fallbacks to wget. On Alpine,
wget comes with busybox doesn't understand `--timestamp` and cause
all dependencies failed to install.

assets/Dockerfile

@@ -28,7 +28,7 @@ USER root
 # But that means hardcoding and that doesn't play well with the nature of Pongo
 # that should be independent of Kong versions.
 RUN apk update \
-    && apk add zip unzip make g++ py-pip jq git bsd-compat-headers m4 openssl-dev curl python3-dev \
+    && apk add zip unzip make g++ py-pip jq git bsd-compat-headers m4 openssl-dev curl wget python3-dev \
     && curl -k -s -S -L https://github.com/fullstorydev/grpcurl/releases/download/v1.7.0/grpcurl_1.7.0_linux_x86_64.tar.gz | tar xz -C /kong/bin \
     && pip install httpie \
     ; cd /kong \