Relax debian package dependencies to git >= 1:1.7.7.6 rather than needing >= 1:2.0.

Git.Merge needs >= 1.7.7.6 if built with such a version; rest of code all
probes git version at runtime.

debian/changelog

@@ -10,6 +10,8 @@ git-annex (5.20150328) UNRELEASED; urgency=medium
     guid has been downloaded before, even when the url has changed.
   * importfeed: Always store itemid in metadata; before this was only
     done when annex.genmetadata was set.
+  * Relax debian package dependencies to git >= 1:1.7.7.6 rather
+    than needing >= 1:2.0.
 
  -- Joey Hess <id@joeyh.name>  Fri, 27 Mar 2015 16:04:43 -0400
 

debian/control

@@ -75,7 +75,7 @@ Build-Depends:
 	lsof [!kfreebsd-i386 !kfreebsd-amd64 !hurd-any],
 	ikiwiki,
 	perlmagick,
-	git (>= 1:2.0),
+	git (>= 1:1.7.7.6),
 	rsync,
 	wget,
 	curl,
@@ -92,7 +92,7 @@ Package: git-annex
 Architecture: any
 Section: utils
 Depends: ${misc:Depends}, ${shlibs:Depends},
-	git (>= 1:2.0),
+	git (>= 1:1.7.7.6),
 	rsync,
 	wget,
 	curl,