Fix stretched icon. Bug 110456, patch by Chris Brien

<christopher_brien@hotmail.com>, r=bzbarsky,ssaux, sr=alecf

security/manager/pki/resources/content/resetpassword.xul

@@ -41,7 +41,9 @@
   <script type="application/x-javascript" src="chrome://pippki/content/resetpassword.js"/>
 
   <hbox flex="1">
-    <image class="alert-icon" style="margin: 5px;"/>
+    <vbox>
+      <image class="alert-icon" style="margin: 5px;"/>
+    </vbox>
     <vbox style="margin: 5px;" flex="1">
       <hbox flex="1">
         <vbox flex="1">