Merge branch 'fix/1d3d-coupl-average-empty-circle-stencil' into 'master'

[1d3d][avg] Skip point source if the circle stencil is empty (zero coupling term)

See merge request !2923

(cherry picked from commit e61c2b87)

ffe49eda [1d3d][avg] Skip point source if the circle stencil is empty (zero coupling term)