No Continue text attribute in ottava lines is not restored on import

MuseScore d697e22d9b

1. Create a score on two systems
2. Insert an ottava spanning on the two systems
3. Right click the ottava -> Line properties and unckeck Text for Continue. OK. Text is gone on the continuation
4. Save and reopen

Actual result : the continue text is present again and it's the default one
Expected result: no text should be displayed.

Discussion: In the MSCX file there is not text saved at all if the user unchecks the property in line properties. When the file is read, the ottava is setup to the default and there is nothing done to remove the text since there is nothing in the file.

One way to solve it, would be to remove the possibility to uncheck the text. The user will be constraint to use a blank text if he wants nothing to be displayed. Any counter proposal?