[Qt] explicitly call proxy in GUI settings SOCKS5 proxy

- to ensure a consistent wording between core and GUI

src/qt/forms/optionsdialog.ui

@@ -209,10 +209,10 @@
        <item>
         <widget class="QCheckBox" name="connectSocks">
          <property name="toolTip">
-          <string>Connect to the Bitcoin network through a SOCKS proxy.</string>
+          <string>Connect to the Bitcoin network through a SOCKS5 proxy.</string>
          </property>
          <property name="text">
-          <string>&amp;Connect through SOCKS proxy (default proxy):</string>
+          <string>&amp;Connect through SOCKS5 proxy (default proxy):</string>
          </property>
         </widget>
        </item>