credential: stop using deprecated property for email

In 44e0b22f (Move to new API, detailed properties take precedence,
2011-09-09) we introduce a new data model for coordinates, in the case
of emails, we have "url_string" fro the "detailed" form and
"coordinate_text", for the "store what user entered" form.

In some places of erp5_credential, we use setDefaultEmailText, which
calls Coordinate.setText which uses the deprecated Coordinate.fromText,
which sets the same value for "url_string" and "coordinate_text", which
seems a questionnable behavior, because the data is saved twice and
some code might be using the wrong property.

This changes every usage to the new coordinate_text property
6 jobs for fix/credential_email_url_string in 0 seconds (queued for 1 second)
Status Job ID Name Coverage
  External
passed ERP5.CodingStyleTest-TestRunner2

02:12:30

failed ERP5.UnitTest-TestRunner2

03:45:50

passed ERP5.CodingStyleTest-TestRunner2

01:10:39

passed ERP5.CodingStyleTest-TestRunner2

02:20:54

failed ERP5.UnitTest-TestRunner2

02:04:53

failed ERP5.UnitTest-TestRunner2

03:49:07