Fix move speed not correctly reset when chasing a unit

def47cb7ae had an issue where the move speed was not correctly reset
after chasing a unit.

Reported By: Angen
Reviewed By: Angen
Differential Revision: https://code.wildfiregames.com/D1861
This was SVN commit r22275.

binaries/data/mods/public/simulation/components/UnitAI.js

@@ -2037,6 +2037,8 @@ UnitAI.prototype.UnitFsmSpec = {
 				},
 
 				"leave": function() {
+					this.ResetMoveSpeed();
+
 					// Show carried resources when walking.
 					this.SetDefaultAnimationVariant();