Fix pcall return value handling in HTTP client

pcall wraps socket.http.request returns as:
  true, 1, status_code, headers, status_line

The old code captured '1' as the status code instead of
the actual HTTP status. Added '_' to skip the first return.

BookhoardAPI.lua

@@ -59,23 +59,23 @@ function BookhoardAPI:_request(method, path, body, timeouts)
 
     socketutil:set_timeout(timeouts[1], timeouts[2])
 
-    local ok, code
+    local ok, _, code
     if url:match("^https://") then
         if ssl_ok then
-            ok, code = pcall(ssl_https.request, request)
+            ok, _, code = pcall(ssl_https.request, request)
         else
             socketutil:reset_timeout()
             return false, { error = "HTTPS not supported on this device" }
         end
     else
-        ok, code = pcall(http.request, request)
+        ok, _, code = pcall(http.request, request)
     end
 
     socketutil:reset_timeout()
 
     if not ok then
-        logger.warn("BookhoardAPI: request failed:", code)
-        return false, { error = tostring(code) }
+        logger.warn("BookhoardAPI: request failed:", _)
+        return false, { error = tostring(_) }
     end
 
     local response_body = table.concat(sink)