Error in opt mode for HIERARCHIC p=0

[roystgnr]

We can't support constants and still have a hierarchic basis that can potentially be C0 ... but application users can typically request a p=0 L2_HIERARCHIC basis and we really need to put a stop to that before we hand back the i=1 FIRST basis function and let them get incorrect results.

[moosebuild]

Job Coverage, step Generate coverage on d565d20 wanted to post the following:

Coverage

	69e327	#3974 d565d2
	Total	Total	+/-	New
Rate	62.19%	62.19%	+0.00%	100.00%
Hits	72470	72472	+2	3
Misses	44068	44069	+1	0

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