Fix asset build issue with faces material remap, in case there is no material into the imported fbx

#jira UE-85920
#rb benoit.deschenes

#ROBOMERGE-OWNER: johan.duparc
#ROBOMERGE-AUTHOR: alexis.matte
#ROBOMERGE-SOURCE: CL 10765941 in //UE4/Release-4.24/...
#ROBOMERGE-BOT: RELEASE (Release-4.24 -> Main) (v610-10636431)

[CL 10767305 by johan duparc in Main branch]

Engine/Source/Developer/MeshBuilder/Private/SkeletalMeshBuilder.cpp

@@ -61,7 +61,7 @@ namespace SkeletalMeshBuilderHelperNS
 			//Nothing to fix if we have 1 or less material
 			return;
 		}
-		
+
 		//Fix the material for the faces
 		TArray<int32> MaterialRemap;
 		MaterialRemap.Reserve(RawMeshMaterials.Num());