do not execute sonar-ws-client unit tests in parallel

sonar-ws-client/pom.xml

@@ -87,19 +87,4 @@
       <scope>test</scope>
     </dependency>
   </dependencies>
-
-  <build>
-    <plugins>
-      <!-- Running JUnit tests in parallel -->
-      <plugin>
-        <groupId>org.apache.maven.plugins</groupId>
-        <artifactId>maven-surefire-plugin</artifactId>
-        <configuration>
-          <parallel>classes</parallel>
-          <threadCount>3</threadCount>
-          <perCoreThreadCount>true</perCoreThreadCount>
-        </configuration>
-      </plugin>
-    </plugins>
-  </build>
 </project>