Fix a bunch of int to unsigned int conversion warnings

src/xmpp/biboumi_component.cpp

@@ -762,7 +762,7 @@ bool BiboumiComponent::handle_mam_request(const Stanza& stanza)
         if (limit < 0 || limit > 100)
           limit = 100;
         auto result = Database::get_muc_logs(from.bare(), iid.get_local(), iid.get_server(),
-                                            limit,
+                                            static_cast<std::size_t>(limit),
                                             start, end,
                                             reference_record_id, paging_order);
         bool complete = std::get<bool>(result);

src/xmpp/jid.cpp

@@ -106,7 +106,7 @@ std::string jidprep(const std::string& original)
           --domain_end;
         if (domain_end != domain && special_chars.count(domain[0]))
           {
-            std::memmove(domain, domain + 1, domain_end - domain + 1);
+            std::memmove(domain, domain + 1, static_cast<std::size_t>(domain_end - domain) + 1);
             --domain_end;
           }
         // And if the final result is an empty string, return a dummy hostname

src/xmpp/xmpp_parser.cpp

@@ -20,7 +20,7 @@ static void end_element_handler(void* user_data, const XML_Char* name)
 
 static void character_data_handler(void *user_data, const XML_Char *s, int len)
 {
-  static_cast<XmppParser*>(user_data)->char_data(s, len);
+  static_cast<XmppParser*>(user_data)->char_data(s, static_cast<std::size_t>(len));
 }
 
 /**