Fix a control/id attribute mismatch, r=me as trivial

browser/components/preferences/main.xul

@@ -109,7 +109,7 @@
       <caption label="&homePage.label;"/>
 
       <hbox align="center">
-        <label value="&location.label;" accesskey="&location.accesskey;" control="browserStartupHomepage"/>
+        <label value="&location.label;" accesskey="&location.accesskey;" control="browserHomePage"/>
         <textbox id="browserHomePage" class="padded" flex="1"
                  type="autocomplete" autocompletesearch="history"
                  preference="browser.startup.homepage"/>