bitbake: Fix dict changing size problems

Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>

bitbake/lib/bb/fetch/__init__.py

@@ -153,14 +153,16 @@ def init(urls, d, setup = True):
     urldata_cache[fn] = urldata
     return urldata
 
-def go(d):
+def go(d, urls = None):
     """
     Fetch all urls
     init must have previously been called
     """
-    urldata = init([], d, True)
+    if not urls:
+        urls = d.getVar("SRC_URI", 1).split()
+    urldata = init(urls, d, True)
 
-    for u in urldata:
+    for u in urls:
         ud = urldata[u]
         m = ud.method
         if ud.localfile: