Build: Fix modules getting their optimization setting overridden.

Asterisk modules that use PJPROJECT services have their compiler
optimization and possibly their symbolic debug options overridden by the
PJPROJECT configure script selected settings.

* We need to filter-out any -O and -g options in PJ_CFLAGS before echoing
out the result so the PJPROJECT_INCLUDE variable does not override the
Asterisk module settings when using bundled PJPROJECT.

NOTE: This patch only has an effect when using bundled PJPROJECT.

ASTERISK-27563

Change-Id: If124169735ecf572ad1535cd43bff94cb44d5b30

third-party/pjproject/Makefile

@@ -158,8 +158,11 @@ build.mak: source/build.mak
 
 configure: source/build.mak
 
+# We need to filter-out any -O and -g options in PJ_CFLAGS before echoing out
+# the result so Asterisk modules don't have the optimization and symbolic debug
+# options overridden by the PJPROJECT configure script selected settings.
 echo_cflags: source/build.mak
-	@echo $(PJ_CFLAGS)
+	@echo $(filter-out -O% -g%,$(PJ_CFLAGS))
 
 libpj%.a: source/build.mak
 	$(ECHO_PREFIX) Compiling lib $(@F)