Revert change making jdt compiler use project settings

Should fix
eclipse-platform/eclipse.platform.releng.aggregator#1653
.
Further work on the topic could be continued as described in
eclipse-platform#973 (comment)

pom.xml

@@ -77,14 +77,6 @@
             <testClassesDirectory>${tycho.surefire.testClassesDirectory}</testClassesDirectory>
           </configuration>
         </plugin>
-		<plugin>
-			<groupId>org.eclipse.tycho</groupId>
-			<artifactId>tycho-compiler-plugin</artifactId>
-			<configuration>
-				<useProjectSettings>true</useProjectSettings>
-			</configuration>
-		</plugin>
-      </plugins>
     </pluginManagement>
   </build>
 </project>