Two defects in how the data source settings were read.
The switch reported a state nobody had chosen. `useCustomTLE` was ANDed with
`tleUrl != Sources.defaultTleUrl`, so an operator who enabled custom sources and then
typed the default URL by hand saw the switch flip itself off. It now reports what they set.
The example.com placeholder rewrite ran on every read. A 4.4.7-era build could persist
`https://example.com/tle.txt`, and the fix for that rewrote the value each time it was
read - so the stored value and the returned value disagreed indefinitely and nothing ever
settled it. It is now a one-time migration following migrateRCFormats, which writes the
correction back and records that it has run.
Not addressed here, and the reason the settings screen still misleads: a custom TLE URL
replaces only the source keyed "All" and the other 27 hardcoded sources are still fetched
unconditionally, so "use custom sources" actually means "my source plus 27 others". Which
way that should go is a decision about intent rather than a defect to patch, and upstream
fetches all of its sources unconditionally, which is where the behaviour came from.
mckero
e8e67b74cd