trivial clean-up: remove import that is now detected to be unused

Change-Id: Icf7c0d231019766bf723de53e99fbce5432dcfc0
diff --git a/org.eclipse.jdt.core/model/org/eclipse/jdt/core/compiler/IScanner.java b/org.eclipse.jdt.core/model/org/eclipse/jdt/core/compiler/IScanner.java
index a2dda6c..b4449b6 100644
--- a/org.eclipse.jdt.core/model/org/eclipse/jdt/core/compiler/IScanner.java
+++ b/org.eclipse.jdt.core/model/org/eclipse/jdt/core/compiler/IScanner.java
@@ -14,8 +14,6 @@
 
 package org.eclipse.jdt.core.compiler;
 
-import org.eclipse.jdt.core.compiler.InvalidInputException;
-
  /**
   * <p>
   * <strong>Caveat:</strong> With the introduction of "restricted keywords" in Java 9