Core sampler: don't leave a DB connection out there flapping in the breeze

apps/cli/utilities/core_sampler/core_sampler/core_sampler.py

@@ -188,11 +188,16 @@ def main():
         action="store",
     )
     ns = parser.parse_args()
-
-    if ns.project_code:
-        CoreSampler(MDDBConnector()).sample_project(ns.project_code[0])
-    elif ns.sdm_name:
-        CoreSampler(MDDBConnector()).sample_eb(ns.sdm_name[0])
+    conn = MDDBConnector()
+    sampler = CoreSampler(conn)
+
+    try:
+        if ns.project_code:
+            sampler.sample_project(ns.project_code[0])
+        elif ns.sdm_name:
+            sampler.sample_eb(ns.sdm_name[0])
+    finally:
+        conn.close()
 
     return 0