The achitecture of deb package is i386, not i686

i686 architecture is not allowed. For example,
'dpkg-architecture -L' shows only i386 architectures.
repropro rejects i686 so we should convert i686 to i386.
Merge pull request #335 from repeatedly/use-i386-at-deb

The 32bit deb architecture is i386, not i686