Fix autoreconf invocation to actually run autopoint

The AUTOPOINT=true autoreconf invocation (which probably expected "true" to be a boolean flag) was running the true binary as the autopoint executable, so after a make bootstrap four of the autopoint m4 helpers are shown as missing by git status. A manual call of autopoint had been added (probably out of frustration with that), but was added before the for-loop (which removes m4 files already present on the host-system), so those files still ended up missing.