neutrino: fix crashes on invalid fonts

with the latest fontrenderer fix, invalid fonts now can lead to
division by zero errors. fix the occurences I found.

git-svn-id: file:///home/bas/coolstream_public_svn/THIRDPARTY/applications/neutrino-experimental@43 e54a6e83-5905-42d5-8d5c-058d10e6a962

src/gui/filebrowser.cpp

@@ -386,6 +386,8 @@ void CFileBrowser::commonInit()
 
 	theight = g_Font[SNeutrinoSettings::FONT_TYPE_EVENTLIST_TITLE]->getHeight();
 	fheight = g_Font[SNeutrinoSettings::FONT_TYPE_FILEBROWSER_ITEM]->getHeight();
+	if (fheight == 0)
+		fheight = 1; /* avoid div by zero on invalid font */
 	foheight = 30;
 
 	liststart = 0;