Revert "Fix delete bug when contact's name is null"

This reverts commit 1f8f7d396e2678e8dff6849692912d46b209bf2c.
Revert 1f8f7d3..8583599

This rolls back to commit 1f8f7d396e2678e8dff6849692912d46b209bf2c.
Add more info about SQLite-net