By Jihed Abidellaoui and Zohra Bensemra NABATIEH, Lebanon, June 18 (Reuters) - Rescue workers in the southern Lebanese city of Nabatieh said they believed their headquarters, clearly identified as a civil defence centre, would be safe from Israeli bombardment - until it was destroyed by an airstrike last month. Picking through the debris, they were salvaging whatever they could when Reuters visited this week.