block: remove Base.Verify()

It's a no-op and there is nothing we can do about it, header contents could
only be checked against chain state, there is nothing to check for internal
consistency.

pkg/core/block/block_base.go

@@ -64,12 +64,6 @@ type baseAux struct {
 	Witnesses     []transaction.Witness `json:"witnesses"`
 }
 
-// Verify verifies the integrity of the Base.
-func (b *Base) Verify() bool {
-	// TODO: Need a persisted blockchain for this.
-	return true
-}
-
 // Hash returns the hash of the block.
 func (b *Base) Hash() util.Uint256 {
 	if b.hash.Equals(util.Uint256{}) {

pkg/core/blockchain.go

@@ -264,9 +264,6 @@ func (bc *Blockchain) init() error {
 		}
 		headerSliceReverse(headers)
 		for _, h := range headers {
-			if !h.Verify() {
-				return fmt.Errorf("bad header %d/%s in the storage", h.Index, h.Hash())
-			}
 			bc.headerList.Add(h.Hash())
 		}
 	}
@@ -506,10 +503,6 @@ func (bc *Blockchain) addHeaders(verify bool, headers ...*block.Header) (err err
 			if int(h.Index) < headerList.Len() {
 				continue
 			}
-			if !h.Verify() {
-				err = fmt.Errorf("header %v is invalid", h)
-				return
-			}
 			if err = bc.processHeader(h, batch, headerList); err != nil {
 				return
 			}