[FLINK-5772] [elasticsearch] Allow Elasticsearch 1.x tests to rerun o…

…n failure

This is allowed because Elasticsearch 1.x has a potential deadlock when
creating indices. Since this flakiness rarely happens, this commit
allows rerunning the Elasticsearch 1.x tests to try to mitigate this
problem instead of just failing them.

This closes #3410.

flink-connectors/flink-connector-elasticsearch/pom.xml

@@ -84,4 +84,16 @@ under the License.
 
 	</dependencies>
 
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-surefire-plugin</artifactId>
+				<configuration>
+					<rerunFailingTestsCount>3</rerunFailingTestsCount>
+				</configuration>
+			</plugin>
+		</plugins>
+	</build>
+
 </project>