Made n_bins=1 case same shape as others

[coveralls]

Pull Request Test Coverage Report for Build 128

• 45 of 49 (91.84%) changed or added relevant lines in 2 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage increased (+18.2%) to 91.315%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
svo_filters/svo.py	9	13	69.23%
<!--	Total:	45	49	91.84%	-->

Files with Coverage Reduction	New Missed Lines	%
svo_filters/svo.py	1	89.72%
<!--	Total:	1		-->

Totals
Change from base Build 120:	18.2%
Covered Lines:	389
Relevant Lines:	426

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💛 - Coveralls