bundled_pjproject: Improve SSL/TLS error handling

bundled_pjproject:  Improve SSL/TLS error handling

OpenSSL has 2 levels or error processing.  It's possible for the
top layer to return SSL_ERROR_SYSCALL but the lower layer return
no error, in which case processing should continue.  Only the top
layer was being examined though so connections were being torn
down when they didn't need to be.  This patch adds the examination
of the lower level codes, and if they return no errors, allows
processing to continue.

ASTERISK-27001
Reported-by: Ian Gilmour
patches:
	pjproject-2.6.patch  submitted by Ian Gilmour (license 6889)

Updated-by: George Joseph and Sauw Ming (Teluu)
Merged to upstream pjproject on 7/27/2017 (commit 5631)

Change-Id: I23844ca0c68ef1ee550f14d46f6dae57d33b7bd2