qt: Do not truncate node flag strings in debugwindow.ui peers details tab.

Not all possible node flags are visible in details of peers tab since v18.2.
qt will now autoadapt the slider to the full string size.

Signed-off-by: saibato <saibato.naga@pm.me>

Author: Saibato

src/qt/forms/debugwindow.ui

@@ -1080,7 +1080,7 @@
               </property>
               <property name="minimumSize">
                <size>
-                <width>300</width>
+                <width>0</width>
                 <height>0</height>
                </size>
               </property>