fix: prevent NullPointerException and ConcurrentModificationException when...

fix: prevent NullPointerException and ConcurrentModificationException when renaming something (PR #1055)

jadx-gui/src/main/java/jadx/gui/utils/search/CodeIndex.java

@@ -23,7 +23,7 @@ public class CodeIndex {
 		values.add(value);
 	}
 
-	public void removeForCls(JavaClass cls) {
+	public synchronized void removeForCls(JavaClass cls) {
 		values.removeIf(v -> v.getJavaNode().getTopParentClass().equals(cls));
 	}