Log Message:
nss: Update to 4.49.2

Changelog:
No new functionality is introduced in this release. This release fixes several
issues:

 - Bug 1606992 - Cache the most recent PBKDF1 password hash, to speed up
repeated SDR
   operations when using profiles using that hash. This is covering additional
cases
   not covered by NSS 3.49.1, important with the increased KDF iteration
counts.
 - Bug 1608327 - Fix compilation problems with NEON-specific code in freebl
 - Bug 1608895 - Fix a taskcluster issue with Python 2 / Python 3

NSS 3.49.2 requires NSPR 4.24 or newer.