Fix SSML stripping inside tags

[DaTeVo]

Fix module_strip_ssml() to ignore XML entities inside SSML tags.

Previously:

<tag attr="Tom &amp; Jerry">Hello</tag>

produced:

&Hello

It now produces:

Hello

[sthibaul]

Thanks for spotting this!

I'm thinking that the loop could instead be reworked a bit. I was actually surprised that it was including i == len. We don't actually need that, but we need to terminate the out string. It seems to me we should rather simplify the loop:

• use i<len in the for loop,
• add out[n++] = 0 after the loop to terminate the out string,
• and then we can just introduce if (omit) continue; where you added your if, and remove the last if, to just copy one character when it's not a known ssml entity.

[DaTeVo]

Thank you for the review. I will take care of it on Wednesday.

[sthibaul]

squashed and pushed, thanks!