closes https://github.com/assimp/assimp/issues/1266: fix wrong delete

Instead of delete delete [] must be used.

code/RemoveVCProcess.cpp

@@ -306,7 +306,7 @@ bool RemoveVCProcess::ProcessMesh(aiMesh* pMesh)
         if (!pMesh->mColors[i])break;
         if (configDeleteFlags & aiComponent_COLORSn(i) || b)
         {
-            delete pMesh->mColors[i];
+            delete [] pMesh->mColors[i];
             pMesh->mColors[i] = NULL;
             ret = true;