Trigger added downtimes immediately if checkable is Not-OK

fixes #8389

lib/icinga/checkable-downtime.cpp

@@ -104,6 +104,14 @@ String Checkable::AddDowntime(const String& author, const String& comment,
 		l_DowntimesCache[uid] = this;
 	}
 
+	/* if this object is already in a NOT-OK state trigger this downtime now */
+	if (GetStateRaw() != ServiceOK) {
+		Log(LogNotice, "Checkable")
+		    << "Checkable '" << GetName() << "' already in a NOT-OK state."
+		    << " Triggering downtime now.";
+		TriggerDowntime(uid);
+	}
+
 	Log(LogNotice, "Checkable")
 	    << "Added downtime with ID '" << downtime->GetLegacyId()
 	    << "' between '" << Utility::FormatDateTime("%Y-%m-%d %H:%M:%S", startTime)