Stray/junk .mp3 files in "podcasts" directory

[Vincas Dargis]

"Downloads" section shows no downloaded podcasts on my phone, but accidentally (by copying home directory to the new phone) saw that here's still some .mp3 files inside `podcasts` directory:

```
phablet@ubuntu-phablet:~$ du -hc .local/share/com.mikeasoft.podbird/podcasts/*.mp
99M .local/share/com.mikeasoft.podbird/podcasts/10147527-44100-2-7cf12ff40c8a5.mp3
83M .local/share/com.mikeasoft.podbird/podcasts/3039.mp3
60M .local/share/com.mikeasoft.podbird/podcasts/3089.mp3
61M .local/share/com.mikeasoft.podbird/podcasts/4419.mp3
79M .local/share/com.mikeasoft.podbird/podcasts/55.-Is-easy-money-good-for-exports-.mp3
42M .local/share/com.mikeasoft.podbird/podcasts/6070.mp3
61M .local/share/com.mikeasoft.podbird/podcasts/6161.mp3
49M .local/share/com.mikeasoft.podbird/podcasts/8051020-48000-2-1fb4739e0681c.mp3
46M .local/share/com.mikeasoft.podbird/podcasts/cppcast-124.mp3
38M .local/share/com.mikeasoft.podbird/podcasts/cppcast-137.mp3
161M .local/share/com.mikeasoft.podbird/podcasts/semdec31.mp3
775M total
```

That's almost a gig of "lost" storage space.