[FLINK-7846] [elasticsearch] Remove unnecessary guava shading

This closes apache#4902.

flink-connectors/flink-connector-elasticsearch2/pom.xml

@@ -91,35 +91,4 @@ under the License.
 
  </dependencies>
 
- <build>
- <plugins>
- <plugin>
- <groupId>org.apache.maven.plugins</groupId>
- <artifactId>maven-shade-plugin</artifactId>
- <executions>
- <execution>
- <id>shade-flink</id>
- <configuration>
- <artifactSet>
- <includes>
- <include>com.google.guava:guava</include>
- </includes>
- </artifactSet>
- <relocations>
- <relocation>
- <pattern>com.google</pattern>
- <shadedPattern>org.apache.flink.elasticsearch.shaded.com.google</shadedPattern>
- <excludes>
- <exclude>com.google.protobuf.**</exclude>
- <exclude>com.google.inject.**</exclude>
- </excludes>
- </relocation>
- </relocations>
- </configuration>
- </execution>
- </executions>
- </plugin>
- </plugins>
- </build>
-
 </project>