App update

Submodule web/app 28cc2df..d9bc526:
  > Change the length of the salt for pbkdf2
  > Use more clear number of pbkdf2 iterations in the config file
  > Set the port as environment variable
  > Remove useless imports

app @ d9bc526d

-Subproject commit 28cc2df31fb182a334ff79ff0ddd73e4ecc8c342
+Subproject commit d9bc526d11e2ccfa1e6f5496dddb21f5e80df0a5