apt-private: Do not include apti18n.h in headers

This causes build failures when turning translations off.

apt-private/private-cachefile.h

@@ -9,8 +9,6 @@
 #include <apt-pkg/sourcelist.h>
 #include <apt-pkg/cacheset.h>
 
-#include <apti18n.h>
-
 // class CacheFile - Cover class for some dependency cache functions	/*{{{*/
 class APT_PUBLIC CacheFile : public pkgCacheFile
 {

apt-private/private-cacheset.h

@@ -11,8 +11,6 @@
 #include <set>
 #include <string>
 
-#include <apti18n.h>
-
 class OpProgress;
 
 class VerIteratorWithCaching