Fix concurrent firmware updates

If another instance deletes the form, it's ok.  Ignore
the exception and continue on.

Change-Id: I3c92e5c657d6b16daa70f26dd450e3b9c6e55a11

pyghmi/ipmi/oem/lenovo/imm.py

@@ -563,7 +563,7 @@ class XCCClient(IMMClient):
             raise Exception('Unexpected response: ' + repr(rsp))
         progress({'phase': 'upload',
                   'progress': 100.0})
-        ipmisession.Session.pause(2)
+        ipmisession.Session.pause(3)
         # aggressive timing can cause the next call to occasionally
         # return 25 and fail
         self._refresh_token()

pyghmi/util/webclient.py

@@ -128,7 +128,10 @@ class SecureHTTPConnection(httplib.HTTPConnection, object):
         # peer updates in progress should already have pointers,
         # subsequent transactions will cause memory to needlessly double,
         # but easiest way to keep memory relatively low
-        del uploadforms[filename]
+        try:
+            del uploadforms[filename]
+        except KeyError:  # something could have already deleted it
+            pass
         if rsp.status != 200:
             raise Exception('Unexpected response in file upload: ' +
                             rsp.read())