added missing return values

Author: Theomat

synth/pbe/solvers/pbe_solver.py

@@ -89,15 +89,15 @@ def solve(
                         self._close_task_solving_(
                             task, enumerator, time, False, program
                         )
-                        return
+                        return False
                     self._programs += 1
                     if self._test_(task, program):
                         should_stop = yield program
                         if should_stop:
                             self._close_task_solving_(
                                 task, enumerator, time, True, program
                             )
-                            return
+                            return True
             except StopIteration as e:
                 self._close_task_solving_(task, enumerator, time, False, program)
                 raise e