provide better error when doctrine/orm is missing

[xabbuh]

Fixes #908.

[xabbuh]

The reported error now looks like this:

$ bin/console cache:clear

In Configuration.php line 313:
                                                                             
  The doctrine/orm package is required when the doctrine.orm config is set.

[greg0ire]

Ah the cs-fix failed… @doctrine/doctrinecore I had the same issue today when contributing, checking cs locally is hard, I had to run composer require -n --prefer-dist --dev doctrine/coding-standard:^5.0 (copied that form .travis.yml) to be able to run phpcbf. Is that the right way to do this?

[Majkl578]

@greg0ire That is solved in master, can't be done in 1.10.x due to PHP 5.x compat.

[alcaeus]

Thanks @xabbuh!