app: getting port from env variable

Author: rukeba

app.py

@@ -1,3 +1,4 @@
+import os
 from flask import Flask, request, render_template
 
 from inspector import ImgLinkInspector
@@ -13,5 +14,5 @@ def root():
 
 
 if __name__ == '__main__':
-    # Threaded option to enable multiple instances for multiple user access support
-    app.run(threaded=True, port=5000)
+    port = int(os.environ.get("PORT", 5000))
+    app.run(threaded=True, port=port)