Fixed error when using multiline subtitles

Hi maboa,

We found that if you use hyperaudioconverter with multiline subtitles there are errors in the hypertranscript.

Example subtitle:

    1
    00:00:08,200 --> 00:00:11,200
    First line
    second line

    2
    00:00:11,200 --> 00:00:14,200
    Single line subtitle

Hypertranscript:

    <span m="8200">First</span> 
    <span m="8950">line<br</span> 
    <span m="9700">/>second</span> 
    <span m="10450">line</span> 
    <span m="11200">Single</span> 
    <span m="12200">line</span> 
    <span m="13200">subtitle</span> 

Now it works with single line and multiline subtitles.

    <span m="8200">First</span> 
    <span m="8950">line</span> 
    <span m="9700">second</span> 
    <span m="10450">line</span> 
    <span m="11200">Single</span> 
    <span m="12200">line</span> 
    <span m="13200">subtitle</span> 

Best regards