Regression from commit a5f9fb72 (fdo#80800 :
DOCX: Preservation of Direct Formatting for non first Table Cells,
2014-07-11), CT_Spacing's two attributes (line and lineRule) may come in
different order; but the change only handled the case when lineRule is
followed by line, and not the other way around.

This fixes a unit test failure in CppunitTest_sw_ooxmlexport's
testSpacingLineRule.

Change-Id: I892d97a97390228a59a129f096be39ce93b822d6