Blender Git Loki

Fix T49226: Incorrect Material viewport shading of Cycles Normal Map node in Edit mode for an object with Array modifier

Was incorrect indexing done in the array. Caused by 5abae51.

Not sure why it needed to be changed here, but array here is supposed to be
a loop data, so bringing back loop index as it originally was. The shading was
wrong in edit mode with BI active as well (so it's not like it's needed for
BI only).

Patch in collaboration with Alexander Gavrilov (angavrilov), thanks!

Should be double-checked and ported to 2.78.