Updating call groups from CSV can cause callees table to go out of range

Probably affects 13, didn't test.

When configuring the Broadcast module to update call groups from CSV, it appears that each time a CSV file is loaded, numbers are deleted and then re-added. This has the effect of auto incrementing the id column each time for each number. As the id column is set to mediumint(9), once the id column hits the 8M mark, table inserts fail. As we give control to the user to run updates at very short intervals (in seconds) and there is no limit to the size csv lists, its possible to reach this limit with normal usage.

Need to modify the SQL query not to delete and re-add values that already exist and need to remain, or eliminate the auto-increment column if it doesn't serve a purpose.