[hotfix] remove extra spaces in project's pom.xml

pom.xml

@@ -315,7 +315,7 @@ under the License.
  <version>3.4.0</version>
  </dependency>
 
- <!-- Make sure we use a consistent avro version between Flink and Hadoop --> 
+ <!-- Make sure we use a consistent avro version between Flink and Hadoop -->
  <dependency>
  <groupId>org.apache.avro</groupId>
  <artifactId>avro</artifactId>
@@ -1615,7 +1615,7 @@ under the License.
  <failOnViolation>true</failOnViolation>
  </configuration>
  </plugin>
- 
+
  <plugin>
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-javadoc-plugin</artifactId>
@@ -1643,7 +1643,7 @@ under the License.
  <plugin>
  <groupId>pl.project13.maven</groupId>
  <artifactId>git-commit-id-plugin</artifactId>
- <!-- Don't use 2.1.14 as it is incompatible with various maven versions --> 
+ <!-- Don't use 2.1.14 as it is incompatible with various maven versions -->
  <version>2.1.10</version>
  <configuration>
  <excludeProperties>