Fix TEvPatch behaviour (#1469)

Author: alexvru

.github/config/muted_ya.txt

@@ -2,7 +2,6 @@ ydb/core/blobstorage/dsproxy/ut TBlobStorageProxySequenceTest.TestBlock42PutWith
 ydb/core/blobstorage/dsproxy/ut_fat TBlobStorageProxyTest.TestBatchedPutRequestDoesNotContainAHugeBlob
 ydb/core/blobstorage/pdisk/ut TSectorMap.*
 ydb/core/blobstorage/ut_blobstorage/ut_read_only_vdisk ReadOnlyVDisk.TestStorageLoad
-ydb/core/blobstorage/ut_blobstorage BlobPatching.PatchBlock42
 ydb/core/blobstorage/ut_blobstorage CostMetricsGetBlock4Plus2.TestGet4Plus2BlockRequests10000Inflight1BlobSize1000
 ydb/core/blobstorage/ut_blobstorage Defragmentation.DoesItWork
 ydb/core/blobstorage/ut_blobstorage SpaceCheckForDiskReassign.*

ydb/core/blobstorage/vdisk/skeleton/skeleton_vpatch_actor.cpp

@@ -365,7 +365,7 @@ namespace NKikimr::NPrivate {
                     (ResultSize, record.ResultSize()),
                     (ParityPart, (blobId.PartId() <= GType.DataParts() ? "no" : "yes")));
 
-            ui8 *buffer = reinterpret_cast<ui8*>(Buffer.UnsafeGetContiguousSpanMut().data());
+            ui8 *buffer = reinterpret_cast<ui8*>(Buffer.GetContiguousSpanMut().data());
             if (PatchedPartId <= GType.DataParts()) {
                 AddMark("Data part");
                 if (GType.ErasureFamily() != TErasureType::ErasureMirror) {
@@ -675,7 +675,7 @@ namespace NKikimr::NPrivate {
             }
 
             if (Buffer) {
-                ui8 *buffer = reinterpret_cast<ui8*>(Buffer.UnsafeGetContiguousSpanMut().data());
+                ui8 *buffer = reinterpret_cast<ui8*>(Buffer.GetContiguousSpanMut().data());
                 ui32 dataSize = OriginalBlobId.BlobSize();
 
                 AddMark("Apply xor diff");