Add an http_port config setting

This should help with brndnmtthws#1061.

Also added a warning about the default port being blocked by browsers.

doc/config_settings.xml

@@ -401,6 +401,17 @@
         <listitem>Port to use for hddtemp connections. Defaults to 7634.
         <para /></listitem>
     </varlistentry>
+    <varlistentry>
+        <term>
+            <command>
+                <option>http_port</option>
+            </command>
+        </term>
+        <listitem>Port to listen to for HTTP connections. Default value is
+        10080, but is blocked by Firefox and Chrome, so you really want to
+        change it.
+        <para /></listitem>
+    </varlistentry>
     <varlistentry>
         <term>
             <command>

src/display-http.cc

@@ -61,6 +61,8 @@ std::string webpage;
 struct MHD_Daemon *httpd;
 static conky::simple_config_setting<bool> http_refresh("http_refresh", false,
                                                        true);
+static conky::simple_config_setting<unsigned short> http_port("http_port",
+                                                              HTTPPORT, true);
 
 MHD_Result sendanswer(void *cls, struct MHD_Connection *connection,
                       const char *url, const char *method, const char *version,
@@ -85,8 +87,15 @@ class out_to_http_setting : public conky::simple_config_setting<bool> {
     Base::lua_setter(l, init);
 
     if (init && do_convert(l, -1).first) {
-      httpd = MHD_start_daemon(MHD_USE_SELECT_INTERNALLY, HTTPPORT, nullptr,
-                               NULL, &sendanswer, nullptr, MHD_OPTION_END);
+      /* warn about old default port */
+      if (http_port.get(*state) == 10080) {
+        NORM_ERR(
+            "warning: port 10080 is blocked by browsers "
+            "like Firefox and Chromium, you may want to change http_port.");
+      }
+      httpd =
+          MHD_start_daemon(MHD_USE_SELECT_INTERNALLY, http_port.get(*state),
+                           nullptr, NULL, &sendanswer, nullptr, MHD_OPTION_END);
     }
 
     ++s;