Fix QueryCancellationServlet use of e.getMessage()

Correct log message to not utilize getMessage() on arbitrary exceptions

Change-Id: I1f5e2172728d3bc4d0cc4a9990518adcd91ae76b
Reviewed-on: https://asterix-gerrit.ics.uci.edu/1809
Sonar-Qube: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Tested-by: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Integration-Tests: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
BAD: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Reviewed-by: Yingyi Bu <buyingyi@gmail.com>
diff --git a/asterixdb/asterix-app/src/main/java/org/apache/asterix/api/http/server/QueryCancellationServlet.java b/asterixdb/asterix-app/src/main/java/org/apache/asterix/api/http/server/QueryCancellationServlet.java
index 4405d29..bfec146 100644
--- a/asterixdb/asterix-app/src/main/java/org/apache/asterix/api/http/server/QueryCancellationServlet.java
+++ b/asterixdb/asterix-app/src/main/java/org/apache/asterix/api/http/server/QueryCancellationServlet.java
@@ -72,9 +72,7 @@
             // response: OK
             response.setStatus(HttpResponseStatus.OK);
         } catch (Exception e) {
-            if (LOGGER.isLoggable(Level.WARNING)) {
-                LOGGER.log(Level.WARNING, e.getMessage(), e);
-            }
+            LOGGER.log(Level.WARNING, "unexpected exception thrown from cancel", e);
             // response: INTERNAL SERVER ERROR
             response.setStatus(HttpResponseStatus.INTERNAL_SERVER_ERROR);
         }