2014-07-15: safer sed thanks to nalaginrut

safer sed thanks to nalaginrut

diff --git a/Makefile.am b/Makefile.am
--- a/Makefile.am
+++ b/Makefile.am
@@ -14,7 +14,7 @@ ChangeLog :
 
 .INTERMEDIATE: input.in.intermediate
 input.in.intermediate: ${wisp_SOURCES}
-	@abs_top_srcdir@/bootstrap.sh @abs_top_srcdir@ @guile@ @python3@ 2>&1 | sed "s/;;;.*//" 2>&1 | grep . 1>&2 ; test ! $$? -eq 0 # grep did not find anything
+	@abs_top_srcdir@/bootstrap.sh @abs_top_srcdir@ @guile@ @python3@ 2>&1 | sed "s/^;;;.*//" 2>&1 | grep . 1>&2 ; test ! $$? -eq 0 # grep did not find anything
 
 .PHONY: syntaxtests.sh
 syntaxtests.sh : wisp.scm runtests.sh