scheduler: fix task cancelling

This fix testInviteFromMessageAfterRemoved (hasHandler was
not correct in checkConversationsEvents because the task was not
cancelled anymore).
Fix ut_scheduler's build

Change-Id: I4dbf3b31180c43fb7fa11061f3ffacb492d925c3

src/scheduled_executor.h

@@ -148,6 +148,7 @@ public:
         }
 
         if (not cont) {
+            cancel_.store(true);
             job_.reset();
         }
 

test/unitTest/scheduler.cpp

@@ -46,7 +46,7 @@ CPPUNIT_TEST_SUITE_NAMED_REGISTRATION(SchedulerTest, SchedulerTest::name());
 void
 SchedulerTest::schedulerTest()
 {
-    jami::ScheduledExecutor executor;
+    jami::ScheduledExecutor executor("test");
 
     constexpr unsigned N = 1024;
     std::mutex mtx;