[GUI] removed the clumsy *OR* from the AccountWizardPage

It does not offer any benefit because clicking on new account
will switch you back to the configuration wizard anyway.

TODO: remove this **** ConfigurationWizard extends
EnterXMPPAccountWizard inheritance.

Change-Id: I01bf00ee323ab48ce14334e75aad921420b344eb
Reviewed-on: http://saros-build.imp.fu-berlin.de/gerrit/1125
Tested-by: Jenkins CI
Reviewed-by: Franz Zieris <zieris@inf.fu-berlin.de>
Reviewed-by: Stefan Rossbach <srossbach@arcor.de>