Hello. The solution to your issue is as follows:
1. Compile & install pjsip as normal.
2. Run "configure" for Asterisk as normal
3. Run "Make menuselect" for Asterisk as normal
4. BEFORE running "make" to compile Asterisk, locate "autoconfig.h" and open it with vi or nano. It will be in the "include/asterisk/" folder.
Find the 2 lines:
/* Define to 1 if PJPROJECT has the PJSIP Transaction Group Lock Support feature. */
/* #undef HAVE_PJ_TRANSACTION_GRP_LOCK */
Change the second line to:
#define HAVE_PJ_TRANSACTION_GRP_LOCK 1
5. Save the file
6. You should be able to run "make" successfully now.