patch the yaw=0 direction while expanding

[zhkmxx9302013]

A little change but looks more reasonable.^_^
I patched the yaw=0 when expanding the current node to get neighbors.

[Before]

[After]

[coveralls]

Pull Request Test Coverage Report for Build 893

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 2 unchanged lines in 1 file lost coverage.
• Overall coverage increased (+0.3%) to 90.524%

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Files with Coverage Reduction	New Missed Lines	%
PathPlanning/ClosedLoopRRTStar/pure_pursuit.py	2	94.53%

Totals
Change from base Build 892:	0.3%
Covered Lines:	6620
Relevant Lines:	7313

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💛 - Coveralls

[AtsushiSakai]

@zhkmxx9302013 Good catch!! Thank you!!