diff -up thunderbird-68.2.0/old-configure.in.nss-version thunderbird-68.2.0/old-configure.in

--- thunderbird-68.2.0/old-configure.in.nss-version	2019-10-22 14:50:42.649086398 +0200

+++ thunderbird-68.2.0/old-configure.in	2019-10-22 14:51:11.567171593 +0200

@@ -1537,7 +1537,7 @@ MOZ_ARG_WITH_BOOL(system-nss,

     _USE_SYSTEM_NSS=1 )

 if test -n "$_USE_SYSTEM_NSS"; then

-    AM_PATH_NSS(3.44.3, [MOZ_SYSTEM_NSS=1], [AC_MSG_ERROR([you don't have NSS installed or your version is too old])])

+    AM_PATH_NSS(3.44.0, [MOZ_SYSTEM_NSS=1], [AC_MSG_ERROR([you don't have NSS installed or your version is too old])])

 fi

 NSS_CFLAGS="$NSS_CFLAGS -I${DIST}/include/nss"