refactor: remove redundant code in MergeMap

remove the redundant code that overwrite duplicate keys in MergeMap
function because this part of the code will be executed in mergeModifier
function

pkg/dipper/mapUtils.go

@@ -354,14 +354,6 @@ func mergeModifier(dst map[string]interface{}) {
 // MergeMap : merge the data from source to destination with some overriding rule
 func MergeMap(dst map[string]interface{}, src interface{}) map[string]interface{} {
 	dst = CombineMap(dst, src)
-	for k, v := range dst {
-		if k[len(k)-1] == '-' {
-			if ev, ok := dst[k[:len(k)-1]]; !ok || ev == nil {
-				dst[k[:len(k)-1]] = v
-			}
-			delete(dst, k)
-		}
-	}
 
 	mergeModifier(dst)