test/agent/Makefile: Fix compilation of Guile modules

Since we're not building Jami statically anymore, agent.exe is
generated under test/agent/.libs and the script `agent' is a wrapper
around it.  Thus, change agent.exe for `agent' for compilation of
scheme.

Change-Id: I8766ca6470ba1a9136d8eb6cb2d45b278fd85456

test/agent/Makefile.am

@@ -27,12 +27,12 @@ MODULES =                                       \
 	scenarios/bulk-calls/scenario.scm       \
 	scenarios/peer-monitor/scenario.scm
 
-GOBJECTS = $(MODULES:%=%.go)
+GOBJECTS = $(MODULES:%.scm=%.go)
 
-%.go: % | agent.exe
-	@echo "agent.exe compile $^"
+%.go: %.scm
+	@echo "agent compile $^"
 	@ASAN_OPTIONS=alloc_dealloc_mismatch=0:detect_leaks=0 \
-	./agent.exe compile $< $@
+	./pre-inst-env agent compile $< $@
 
 compile: $(GOBJECTS)