Three days after Whittier Street Health Center announced that it would lay off 20 employees in the midst of a unionization effort, the community health center reversed the cuts. In a statement on Sunday, the organization’s president and CEO, Frederica Williams, credited Mayor Martin J. Walsh. “Thanks to the Mayor’s leadership and guidance and support from others, we have a pathway forward that will put Whittier on a stable financial footing for now,” Williams said.