Reset relationship columns array

[jakejohns]

Reset on in AbstractRelationship::foreignSelectSimple

I was playing around (jakejohns/atlas-demo) trying to come up with a way to use events to persist related records.

Without this patch, I get the following:

PHP Fatal error:  Uncaught exception 'Atlas\Orm\Exception' with message 'Atlas\Orm\Table\Row::$ does not exist.' in vendor/atlas/orm/src/Exception.php:74
Stack trace:
#0 vendor/atlas/orm/src/Table/Row.php(339): Atlas\Orm\Exception::propertyDoesNotExist(Object(Atlas\Orm\Table\Row), '')
#1 vendor/atlas/orm/src/Table/Row.php(104): Atlas\Orm\Table\Row->assertHas('')
#2 vendor/atlas/orm/src/Relationship/AbstractRelationship.php(325): Atlas\Orm\Table\Row->__get('')
#3 vendor/atlas/orm/src/Relationship/AbstractRelationship.php(305): Atlas\Orm\Relationship\AbstractRelationship->foreignSelectSimple(Object(Atlas\Orm\Mapper\MapperSelect), Array)
#4 vendor/atlas/orm/src/Relationship/AbstractRelationship.php(279): Atlas\Orm\Relationship\AbstractRelationship->foreignSelect(Array)
#5 vendor/atlas/orm/src/Rel in vendor/atlas/orm/src/Exception.php on line 74

Although this fixes it, I can't actually explain why. I think I'm too tired to figure it out right now, so hopefully someone else can look.

[pmjones]

Wow that's weird.