Stop overriding is_active default when saving new relationship

[colemanw]

Overview

Makes the is_active default more consistent when creating a new relationship.
For some obscure reason the relationsip BAO was forcing the is_active field to default to 0 even though the schema sets a more sensible default of 1.

Before

Creating a new relationship is not active by default.

After

Creating a new relationship will be active by default.

[civibot]

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