Be slightly more defensive when clearing the forkJoinPoolThread ref in DelegatingScheduler

Author: jhalterman

src/main/java/net/jodah/failsafe/internal/util/DelegatingScheduler.java

@@ -139,13 +139,14 @@ public ScheduledFuture<?> schedule(Callable<?> callable, long delay, TimeUnit un
           }
         }
         promise.complete(callable.call());
+      } catch (Throwable t) {
+        promise.completeExceptionally(t);
+      } finally {
         if (isForkJoinPool) {
           synchronized (promise) {
             promise.forkJoinPoolThread = null;
           }
         }
-      } catch (Throwable t) {
-        promise.completeExceptionally(t);
       }
       return null;
     };