Adjust pis query to check last element

Signed-off-by: Fred Boniface <fred@fjla.uk>

src/services/pis.services.js

@@ -16,9 +16,9 @@ async function findPisByOrigDest(start,end) {
         ]
       },
       $expr: {
-            $eq: [
+        $and: [
-              { $arrayElemAt: [ "$stops", 0 ] },
+          { $eq: [{ $arrayElemAt: [ "$stops", -1 ] }, lastCrs] },
-              firstCrs
+          { $eq: [{ $arrayElemAt: [ "$stops", 0 ] }, firstCrs] }
         ]
       }
     }