Fix file descriptor leak in anydbm

This didn't close a local dbm file on error.
Visible only when tests are run on an NFS mount.

Author: schlatterbeck

roundup/backends/back_anydbm.py

@@ -408,11 +408,13 @@ def getnode(self, classname, nodeid, db=None, cache=1):
         if db is None:
             db = self.getclassdb(classname)
         if nodeid not in db:
+            db.close()
             raise IndexError("no such %s %s" % (classname, nodeid))
 
         # check the uncommitted, destroyed nodes
         if (classname in self.destroyednodes and
                 nodeid in self.destroyednodes[classname]):
+            db.close()
             raise IndexError("no such %s %s" % (classname, nodeid))
 
         # decode