remove impExt null check

Author: tomaszbmf

src/main/java/org/prebid/server/bidder/mobilefuse/MobilefuseBidder.java

@@ -64,10 +64,6 @@ private Imp modifyImp(Imp imp) {
         }
 
         final ExtImpMobilefuse impExt = parseImpExt(imp);
-        if (impExt == null) {
-            return null;
-        }
-
         final ObjectNode skadn = parseSkadn(imp.getExt());
         return imp.toBuilder()
                 .tagid(Objects.toString(impExt.getPlacementId(), "0"))