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/">

virtManager/config.py

@@ -467,9 +467,9 @@ class vmmConfig(object):
             if path in current_list:
                 continue
             current_list.append(path)
-        self.conf.set("/paths/perms_fix_ignore", current_list)
+        self.conf.set("/paths/perms-fix-ignore", current_list)
     def get_perms_fix_ignore(self):
-        return self.conf.get("/paths/perms_fix_ignore")
+        return self.conf.get("/paths/perms-fix-ignore")
 
 
     # Manager view connection list