Find a better solution for the configure hang than backing out the fix for bug 762358
For 4.0.2 and 4.5-alpha-2 we had to back out Mozilla's fix for bug 762358 as it broke our deterministic build setup. It seems it is running |configure| again during the |make build| step which should not be needed as we are not changing .mozconfig (again). Maybe having a .mozconfig file in the first place is already counted as "changing .mozconfig" here. |configure| does not like libfaketime but we need the latter for the |make build| step in order to cope with timestamps embedded, e.g. in libraries.