fix wrong log format

Signed-off-by: Markus Blaschke <mblaschke82@gmail.com>

Author: mblaschke

Dockerfile

@@ -31,7 +31,7 @@ RUN ["./azure-keyvault-exporter", "--help"]
 # final-azcli
 #############################################
 FROM mcr.microsoft.com/azure-cli AS final-azcli
-ENV LOG_JSON=1
+ENV LOG_FORMAT=json
 WORKDIR /
 COPY --from=test /app .
 USER 1000:1000
@@ -41,7 +41,7 @@ ENTRYPOINT ["/azure-keyvault-exporter"]
 # final-static
 #############################################
 FROM gcr.io/distroless/static AS final-static
-ENV LOG_JSON=1
+ENV LOG_FORMAT=json
 WORKDIR /
 COPY --from=test /app .
 USER 1000:1000