Magma blocks make the area around it a bit dark

^{Update by [Mojang] Mega_Spud (Jay Wells):}
Summary:
Magma blocks make the area around them darker than other blocks do.

Steps to Reproduce:

1. Place a grass block down and observe the shadow
2. Now place a magma block down in the same position and observe the shadow again

Observed Results:
Notice how the shadow cast by the Magma block is noticeably different to the grass block

Expected Results:
It should not cast a darker shadow.

Screenshots/Videos attached: Yes

Notes:

---

Original Description:
In the wiki it says that magma blocks are supposed to emit a light level of 3 but instead it makes the area around it a bit dark