In Isometric Staggered and Hexagonal Staggered Projection Modes redundant rectangle is rendered

About issue:

• Similarly issue also can be seen in Isometric Staggered projection mode
• Such issue does not occurs in Orthogonal and Isometric Diamond projection modes
• In viewport in UE4Editor this redundant rectangle isn't  rendered

No regression:

• The same situation repeats in 4.25.3

1. Open any project in UE4Editor
2. Create new Tile Map (Paper2D -> Tile Map) and open it in Tile Map Editor
3. Enable Tile Grid
4. Set Projection Mode to Hexagonal Staggered
5. Set Hex Side Length to 16  

Actual result:

Hexagonal grid and rectangle (HexStaggered.png)

Expected result:

Hexagonal grid (HexExpected.png)