Upstream patch from: http://libtorrent.rakshasa.no/ticket/1271

Fix the following gcc-3.4.6 ICE:

In file included from ./../rpc/command_map.h:45,
                 from ./../rpc/parse_commands.h:43,
                 from dht_manager.cc:46:
./../rpc/command.h: In function `rpc::target_type rpc::get_target_left(const rpc::target_type&)':
./../rpc/command.h:153: internal compiler error: Segmentation fault

--- a/src/rpc/command.h
+++ b/src/rpc/command.h
@@ -87,10 +87,8 @@
   rt_triple(const T1& a, const T2& b, const T3& c) :
     base_type(a, b), third(c) {}
 
-  template <typename U1, typename U2>
-  rt_triple(const std::pair<U1, U2>& b) : base_type(b), third() {}
+  rt_triple(const base_type& b) : base_type(b), third() {}
 
-  template <typename U1, typename U2, typename U3>
   rt_triple(const rt_triple& src) :
     base_type(src.first, src.second), third(src.third) {}
 };