Java: Remove duplicate import statement in ExternalAPI.qll.

Author: michaelnebel

java/ql/src/Telemetry/ExternalAPI.qll

@@ -2,7 +2,6 @@
 
 private import java
 private import semmle.code.java.dataflow.DataFlow
-private import semmle.code.java.dataflow.DataFlow
 private import semmle.code.java.dataflow.ExternalFlow
 private import semmle.code.java.dataflow.FlowSources
 private import semmle.code.java.dataflow.FlowSummary