Handle unexpected prepare write failures

Author: dkropachev

driver-core/src/main/java/com/datastax/driver/core/RequestHandler.java

@@ -833,6 +833,14 @@ public void onSet(
                   connection.release(true);
                   logError(connection.endPoint, e);
                   retry(false, null);
+                } catch (RuntimeException e) {
+                  connection.release();
+                  logger.warn(
+                      "Unexpected error while preparing query on {} - [{}]. Find next host to query.",
+                      connection.endPoint,
+                      e.toString());
+                  logError(connection.endPoint, e);
+                  retry(false, null);
                 }
                 // we're done for now, the prepareAndRetry callback will handle the rest
                 return;