config: catch intended exception when failing to parse config When a new config parser was introduced in fca54469480e (ui: introduce new config parser, 2009-04-23), the reading side would raise a ConfigError which was then caught in the ui code. Then, in 2123aad24d56 (error: add new ParseError for various parsing errors, 2010-06-04), a ParseError was raised instead, but the call site was not updated. Let's start catching that ParseError. We still don't print it in a friendly way, but that's not worse than before. Differential Revision: https://phab.mercurial-scm.org/D7625