[Form Voting] Login page of form voting does not trim whitespaces

[emmdim]

Steps to reproduce

• In https://manager.dev.vocdoni.net
• Steps to reproduce the behaviour:
  1. Create a form voting with data that include white spaces. For example
     Name, Last Name, Email Emm, Dim, test@test.com
  2. When accesing the login page the data Emm,Dim,test@test.com do not allow to acces the vote page.
  3. On the other hand the data Emm, Dim and test@test.com with whitespace in front do resolve correctly to the vote page

System:

• Browser: Chromium 88.0.4324.182
• Commit hash: 49c6efe