We still want to build on compilers w/o c99 support, such as
(notoriously, shamefully) MSVC.
So I'm commenting out the designated initializers in
circuitmux_ewma.c. The alternative would have been to use some kind
of macros to use designated initializers only when they're
supported, but that's error-prone, and can lead to code having
different meanings under different compilers.
Bug 7286; fix on 0.2.4.4-alpha; spotted by Gisle Vanem.
