Properly rethrow exception from ShadowAsyncTask
diff --git a/src/main/java/com/xtremelabs/robolectric/shadows/ShadowAsyncTask.java b/src/main/java/com/xtremelabs/robolectric/shadows/ShadowAsyncTask.java
index 9dd8d46..c65cd51 100644
--- a/src/main/java/com/xtremelabs/robolectric/shadows/ShadowAsyncTask.java
+++ b/src/main/java/com/xtremelabs/robolectric/shadows/ShadowAsyncTask.java
@@ -46,7 +46,7 @@
 					// Ignore.
 				} catch (Throwable t) {
 					throw new RuntimeException("An error occured while executing doInBackground()",
-							t.getCause());
+							t);
 				}
         	}
         };