Fix crash when creating guest from ISO media (bz 958641)

Accessing another unknown gsettings key. Should be the last one
though...

data/org.virt-manager.virt-manager.gschema.xml

@@ -211,6 +211,13 @@
       <summary>Default screenshot path</summary>
       <description>Default path for saving screenshots from VMs</description>
     </key>
+
+    <key name="perms-fix-ignore" type="b">
+      <default>false</default>
+      <summary>Ask about fixing permissions</summary>
+      <description>Whether to ask about fixing path permissions</description>
+    </key>
+
   </schema>
 
   <schema id="org.virt-manager.virt-manager.confirm" path="/org/virt-manager/virt-manager/confirm/">