fix streamline position in plot_velocity() - regression by 63171ad
fix streamline position in plot_velocity() - regression by 63171ad

BubuLK/sfepy,rc/sfepy,lokik/sfepy,sfepy/sfepy,sfepy/sfepy,BubuLK/sfepy,vlukes/sfepy,lokik/sfepy,sfepy/sfepy,vlukes/sfepy,vlukes/sfepy,rc/sfepy,rc/sfepy,lokik/sfepy,lokik/sfepy,BubuLK/sfepy