fix(apparmor): fix file dialog on KDE desktop

Opening file dialog produces error:
```
type=AVC msg=audit(1549805942.022:1474): apparmor="DENIED"
operation="exec" profile="qtox"
name="/usr/lib/x86_64-linux-gnu/libexec/kf5/kioslave" pid=2784
comm="qtox" requested_mask="x" denied_mask="x" fsuid=1000 ouid=0
```

Add rule to allow launching kioslave helper.

security/apparmor/2.12.1/usr.bin.qtox

@@ -28,6 +28,8 @@ profile qtox /usr{,/local}/bin/qtox {
 
   #TODO: use xdg-open abstraction when it's available
   /usr/bin/xdg-open PUx,
+  #TODO: use named profile or abstraction when it's available
+  /usr/lib/@{multiarch}/libexec/kf5/kioslave PUx,
 
   # Additional libraries
 

security/apparmor/2.13.2/usr.bin.qtox

@@ -35,6 +35,8 @@ profile qtox /usr{,/local}/bin/qtox {
 
   #TODO: use xdg-open abstraction when it's available
   /usr/bin/xdg-open PUx,
+  #TODO: use named profile or abstraction when it's available
+  /usr/lib/@{multiarch}/libexec/kf5/kioslave PUx,
 
   # Additional libraries