MULE-6773 - Fix maxThreadsIdle for disptchers because it is being set with maxThreadsActive value
(cherry picked from commit 784d844b2a828094203d5f56e71076cca9a982f9)
(cherry picked from commit 362094dc16afcd6cf5699a936d04767729d2c4e0)
(cherry picked from commit a118e794de7b1f1c28b7539915164ecc26cce91d)