fix build with newer git installations

Makefile

@@ -201,7 +201,7 @@ ifeq ($(wildcard .svn),.svn)
   endif
 else
 ifeq ($(wildcard .git/svn/.metadata),.git/svn/.metadata)
-  SVN_REV=$(shell LANG=C git-svn info | awk '$$1 == "Revision:" {print $$2; exit 0}')
+  SVN_REV=$(shell LANG=C git svn info | awk '$$1 == "Revision:" {print $$2; exit 0}')
   ifneq ($(SVN_REV),)
     VERSION:=$(VERSION)_SVN$(SVN_REV)
   endif