Don't use redundant isStarImport in from import statement stub

We now store stubs for star import elements so having this flag in
the stub for PyFromImportStatement became redundant.

python/psi-api/src/com/jetbrains/python/psi/stubs/PyFromImportStatementStub.java

@@ -26,6 +26,12 @@ import org.jetbrains.annotations.Nullable;
 public interface PyFromImportStatementStub extends StubElement<PyFromImportStatement> {
   @Nullable
   QualifiedName getImportSourceQName();
+
+  /**
+   * @deprecated Use stub-based {@link PyFromImportStatement#getStarImportElement()} instead.
+   */
+  @Deprecated
   boolean isStarImport();
+
   int getRelativeLevel();
 }

python/src/com/jetbrains/python/psi/impl/PyFromImportStatementImpl.java

@@ -64,10 +64,6 @@ public class PyFromImportStatementImpl extends PyBaseElementImpl<PyFromImportSta
   }
 
   public boolean isStarImport() {
-    final PyFromImportStatementStub stub = getStub();
-    if (stub != null) {
-      return stub.isStarImport();
-    }
     return getStarImportElement() != null;
   }