add a breaks libapt-inst for FileFd changes in 0.9.9

Partial upgrades…

The fix for 704608 assumes that bf35c19b817cc1474b3deabce0b0953c248bad42
was applied to libapt-inst which isn't the case for partial upgrades of
course, so break it to ensure that it is the case.

Closes: 720449

debian/control

@@ -41,7 +41,7 @@ Architecture: any
 Multi-Arch: same
 Pre-Depends: ${misc:Pre-Depends}
 Depends: ${shlibs:Depends}, ${misc:Depends}
-Breaks: apt (<< 0.9.4~)
+Breaks: apt (<< 0.9.4~), libapt-inst1.5 (<< 0.9.9~)
 Section: libs
 Description: package management runtime library
  This library provides the common functionality for searching and