fix(test,doc): port env name change (#114)

Follow up from #113. That actually still had an issue, wherein the fallback was expecting a PORT env to be set, which would not be available in v2 environment.

Author: tanmaykm

docs/src/guides/jobs.md

@@ -255,7 +255,7 @@ job = JuliaHub.submit_job(
     using Oxygen, HTTP
     # Environment variable name `PORT` was used in older JuliaHub environments
     # and has been replaced with `JULIAHUB_APP_PORT` in newer environments 
-    PORT = parse(Int, get(ENV, "JULIAHUB_APP_PORT", ENV["PORT"]))
+    PORT = parse(Int, get(ENV, "JULIAHUB_APP_PORT", get(ENV, "PORT", "")))
     @get "/" function(req::HTTP.Request)
         return "success"
     end

test/jobenvs/job-exposed-port/server.jl

@@ -2,7 +2,7 @@ using Oxygen, HTTP
 
 # Environment variable name `PORT` was used in older JuliaHub environments
 # and has been replaced with `JULIAHUB_APP_PORT` in newer environments 
-const PORT = parse(Int, get(ENV, "JULIAHUB_APP_PORT", ENV["PORT"]))
+const PORT = parse(Int, get(ENV, "JULIAHUB_APP_PORT", get(ENV, "PORT", "")))
 const NREQUESTS = Ref{Int}(0)
 
 function results_json()