Minor code changes

plugins/maven/src/main/java/org/jetbrains/idea/maven/dom/converters/MavenArtifactCoordinatesConverter.java

@@ -168,6 +168,7 @@ public abstract class MavenArtifactCoordinatesConverter extends ResolvingConvert
       return resolveInLocalRepository(id, projectsManager, psiManager);
     }
 
+    @Nullable
     protected PsiFile resolveBySpecifiedPath() {
       return null;
     }

plugins/maven/src/main/java/org/jetbrains/idea/maven/dom/converters/MavenDependencySystemPathConverter.java

@@ -41,7 +41,7 @@ public class MavenDependencySystemPathConverter extends ResolvingConverter<PsiFi
     if (s == null) return null;
     VirtualFile f = LocalFileSystem.getInstance().findFileByPath(s);
     if (f == null) return null;
-    return context.getXmlElement().getManager().findFile(f);
+    return context.getPsiManager().findFile(f);
   }
 
   public String toString(@Nullable PsiFile file, ConvertContext context) {