scripted-diff: Avoid interface keyword to fix windows gitian build

Rename `interface` to `interfaces`

Build failure reported by Chun Kuan Lee <ken2812221@gmail.com>
https://github.com/bitcoin/bitcoin/pull/10244#issuecomment-379434756

-BEGIN VERIFY SCRIPT-

git mv src/interface src/interfaces
ren() { git grep -l "$1" | xargs sed -i "s,$1,$2,g"; }
ren interface/            interfaces/
ren interface::           interfaces::
ren BITCOIN_INTERFACE_    BITCOIN_INTERFACES_
ren "namespace interface" "namespace interfaces"

-END VERIFY SCRIPT-

src/qt/bantablemodel.cpp

@@ -8,7 +8,7 @@
 #include <qt/guiconstants.h>
 #include <qt/guiutil.h>
 
-#include <interface/node.h>
+#include <interfaces/node.h>
 #include <sync.h>
 #include <utiltime.h>
 
@@ -46,7 +46,7 @@ public:
     Qt::SortOrder sortOrder;
 
     /** Pull a full list of banned nodes from CNode into our cache */
-    void refreshBanlist(interface::Node& node)
+    void refreshBanlist(interfaces::Node& node)
     {
         banmap_t banMap;
         node.getBanned(banMap);
@@ -82,7 +82,7 @@ public:
     }
 };
 
-BanTableModel::BanTableModel(interface::Node& node, ClientModel *parent) :
+BanTableModel::BanTableModel(interfaces::Node& node, ClientModel *parent) :
     QAbstractTableModel(parent),
     m_node(node),
     clientModel(parent)