Remove superfluous imports

Author: rvermeulen

java/ql/src/semmle/code/java/security/QueryInjection.qll

@@ -1,8 +1,7 @@
 /** Provides classes to reason about database query language injection vulnerabilities. */
 
-import java
 import semmle.code.java.dataflow.DataFlow
-import semmle.code.java.dataflow.FlowSources
+import semmle.code.java.frameworks.Jdbc
 import semmle.code.java.frameworks.android.SQLite
 import semmle.code.java.frameworks.javaee.Persistence
 import semmle.code.java.frameworks.SpringJdbc