[xsp] lower the minimum autoconf version requirement
[xsp] lower the minimum autoconf version requirement

stormleoxia/xsp,arthot/xsp,arthot/xsp,arthot/xsp,stormleoxia/xsp,murador/xsp,stormleoxia/xsp,murador/xsp,murador/xsp,stormleoxia/xsp,murador/xsp,arthot/xsp