net-p2p/litecoin: fix build on GCC architectures

Recent upgrade of some dependency causes GCC to fail to build this port:
httpserver.cpp:74:10: error: 'deque' in namespace 'std' does not name a template type

74 |     std::deque<std::unique_ptr<WorkItem>> queue;
   |          ^~~~~

httpserver.cpp:33:1: note: 'std::deque' is defined in header '<deque>'; did you forget to '#include <deque>'?

 32 | #include <support/events.h>
+++ |+#include <deque>
 33 |

httpserver.cpp: In member function 'bool WorkQueue<WorkItem>::Enqueue(WorkItem*)':
httpserver.cpp:92:13: error: 'queue' was not declared in this scope; did you mean 'Enqueue'?

92 |         if (queue.size() >= maxDepth) {
   |             ^~~~~
   |             Enqueue

httpserver.cpp:95:9: error: 'queue' was not declared in this scope; did you mean 'Enqueue'?

95 |         queue.emplace_back(std::unique_ptr<WorkItem>(item));
   |         ^~~~~
   |         Enqueue

httpserver.cpp: In member function 'void WorkQueue<WorkItem>::Run()':
httpserver.cpp:106:35: error: 'queue' was not declared in this scope; did you mean 'Enqueue'?

106 |                 while (running && queue.empty())
    |                                   ^~~~~
    |                                   Enqueue

httpserver.cpp:110:31: error: 'queue' was not declared in this scope; did you mean 'Enqueue'?

110 |                 i = std::move(queue.front());
    |                               ^~~~~
    |                               Enqueue

Include deque in httpserver.c to fix it.

PR: 242722
Approved by: hsw@bitmark.com (maintainer)