Ignore runs of phonetic that appears in Japanese

[ledsun]

In Japanese, Excel automatically creates Kanji's phonetic styles.
They are not displayed in the cell of the Excel application.

For example:

They appears in OOXML as rPh in xl/sharedStrings.xml like below:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<sst xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main" count="2" uniqueCount="2">
  <si>
    <t>吉田兼好</t>
    <rPh sb="0" eb="2">
      <t xml:space="preserve">ヨシダ </t>
    </rPh>
    <rPh sb="2" eb="4">
      <t xml:space="preserve">ケンコウ </t>
    </rPh>
    <phoneticPr fontId="1"/>
  </si>
</sst>

I think that most users need only the values in the cells of the Excel application.
So, I changed 'creek' to ignore the rPh tag in the si tag.