query.go: fix to skip over files returning IsNotExist errors on queries for width, height.
query.go: fix to skip over files returning IsNotExist errors on queries for width, height.

I am a first time committer and I am using the fix to issue number 402 as a bug to learn to learn how to commit to this process. I am not sure if this is the correct way to fix this bug -- the submitter of the bug believes it is -- so please review my code with scrutiny. Thank you.

Change-Id: I6c56b7866d530e1b1c66c563f201e6d1e13d3fa9

camlistore/camlistore,camlistore/camlistore,mpl/camlistore,pombredanne/camlistore,fgeller/camlistore,angelcabo/camlistore,slspeek/camlistore_namedsearch,slspeek/camlistore_tls_test,angelcabo/camlistore,camlistore/camlistore,stevearm/camlistore,raff/camlistore,angelcabo/camlistore,nimbus/camlistore,slspeek/camlistore_tls_test,angelcabo/camlistore,kbajey/testrepo,slspeek/camlistore_namedsearch,minusnine/camlistore,ginabythebay/camlistore,slspeek/camlistore_tls_test,mpl/camlistore,toshnix/camlistore,nimbus/camlistore,henrylee2cn/camlistore,fgeller/camlistore,minusnine/camlistore,raff/camlistore,pombredanne/camlistore,slspeek/camlistore_tls_test,slspeek/camlistore_tls_test,angelcabo/camlistore,nimbus/camlistore,ginabythebay/camlistore,mortenpi/camlistore,mortenpi/camlistore,toshnix/camlistore,minusnine/camlistore,edrex/camlistore,angelcabo/camlistore,marook/camlistore,toshnix/camlistore,raff/camlistore,stevearm/camlistore,stevearm/camlistore,henrylee2cn/camlistore,slspeek/camlistore_namedsearch,marook/camlistore,slspeek/camlistore_tls_test,kbajey/testrepo,slspeek/camlistore_namedsearch,stevearm/camlistore,minusnine/camlistore,kbajey/testrepo,camlistore/camlistore,stevearm/camlistore,kbajey/testrepo,raff/camlistore,raff/camlistore,ginabythebay/camlistore,slspeek/camlistore_tls_test,mpl/camlistore,ginabythebay/camlistore,nimbus/camlistore,minusnine/camlistore,pombredanne/camlistore,toshnix/camlistore,stevearm/camlistore,kbajey/testrepo,mpl/camlistore,edrex/camlistore,slspeek/camlistore_namedsearch,henrylee2cn/camlistore,ginabythebay/camlistore,kbajey/testrepo,mortenpi/camlistore,slspeek/camlistore_namedsearch,minusnine/camlistore,minusnine/camlistore,pombredanne/camlistore,ginabythebay/camlistore,edrex/camlistore,pombredanne/camlistore,fgeller/camlistore,nimbus/camlistore,mpl/camlistore,marook/camlistore,raff/camlistore,angelcabo/camlistore,nimbus/camlistore,kbajey/testrepo,marook/camlistore,raff/camlistore,fgeller/camlistore,nimbus/camlistore,pombredanne/camlistore,kbajey/testrepo,pombredanne/camlistore,nimbus/camlistore,fgeller/camlistore,fgeller/camlistore,marook/camlistore,mortenpi/camlistore,toshnix/camlistore,ginabythebay/camlistore,fgeller/camlistore,edrex/camlistore,mortenpi/camlistore,fgeller/camlistore,camlistore/camlistore,raff/camlistore,toshnix/camlistore,edrex/camlistore,fgeller/camlistore,henrylee2cn/camlistore,edrex/camlistore,marook/camlistore,nimbus/camlistore,minusnine/camlistore,stevearm/camlistore,angelcabo/camlistore,mpl/camlistore,slspeek/camlistore_tls_test,ginabythebay/camlistore,camlistore/camlistore,ginabythebay/camlistore,henrylee2cn/camlistore,slspeek/camlistore_namedsearch,toshnix/camlistore,camlistore/camlistore,henrylee2cn/camlistore,raff/camlistore,minusnine/camlistore,edrex/camlistore,marook/camlistore,toshnix/camlistore,stevearm/camlistore,camlistore/camlistore,mortenpi/camlistore,mortenpi/camlistore,slspeek/camlistore_namedsearch,edrex/camlistore,stevearm/camlistore,henrylee2cn/camlistore,mpl/camlistore,toshnix/camlistore,slspeek/camlistore_namedsearch,mpl/camlistore,mortenpi/camlistore,camlistore/camlistore,henrylee2cn/camlistore,henrylee2cn/camlistore,pombredanne/camlistore,mpl/camlistore,marook/camlistore,mortenpi/camlistore,angelcabo/camlistore,pombredanne/camlistore