Reset cur.pit() when pasting into tables.

The number of paragraphs can change here, so pit() can become invalid.

Fixes: #9983
(cherry picked from commit 6e4e086900)

src/insets/InsetTabular.cpp

@@ -6174,6 +6174,7 @@ bool InsetTabular::pasteClipboard(Cursor & cur)
 			inset->setChange(Change(buffer().params().track_changes ?
 						Change::INSERTED : Change::UNCHANGED));
 			cur.pos() = 0;
+			cur.pit() = 0;
 		}
 	}
 	return true;