Allow hostnames in LDN direct connect

src/yuzu/multiplayer/direct_connect.ui

@@ -63,7 +63,7 @@
                <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;IPv4 address of the host&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
               </property>
               <property name="maxLength">
-               <number>16</number>
+               <number>253</number>
               </property>
              </widget>
             </item>

src/yuzu/multiplayer/validation.h

@@ -36,11 +36,9 @@ private:
     QRegExp nickname_regex = QRegExp(QStringLiteral("^[a-zA-Z0-9._- ]{4,20}$"));
     QRegExpValidator nickname;
 
-    /// ipv4 address only
-    // TODO remove this when we support hostnames in direct connect
+    /// ipv4 address and hostname
     QRegExp ip_regex = QRegExp(QStringLiteral(
-        "(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|"
-        "2[0-4][0-9]|25[0-5])"));
+        "[a-zA-Z0-9.-]{2,253}$"));
     QRegExpValidator ip;
 
     /// port must be between 0 and 65535