Update Dockerfile

Author: thomasleplus

openid-connect-provider-debugger/Dockerfile

@@ -14,14 +14,14 @@ RUN apk -U upgrade \
     && apk add \
     curl=8.12.1-r0 \
     patch=2.7.6-r10 \
-    && if [[ $(apk -u list) ]] ; then \
+    && if apk -u list | grep -q -e . ; then \
       apk -u list ; \
       exit 1 ; \
     fi \
     && rm -rf /var/cache/apk/*
 
 RUN luarocks install lua-resty-openidc --pin "${LUA_RESTY_OPENIDC_VERSION}" \
-    && IFS=$'\n\t' if luarocks list --outdated | grep -q -e '^lua-resty-openidc$' ; then \
+    && if luarocks list --outdated | grep -q -e '^lua-resty-openidc$' ; then \
       luarocks list --outdated ; \
       exit 1 ; \
     fi