avoid regen during install

Signed-off-by: Francois Perrad <francois.perrad@gadz.org>

--- a/sources/Makefile
+++ b/sources/Makefile
@@ -120,7 +120,7 @@
 	ln -sf $(SHARED_LIB) $(LIBRARIES)/lib4th.so
 endif
 
-mostlyinstall: libinstall all
+mostlyinstall: libinstall
 	cp 4th 4tsh pp4th $(BINARIES)
 
 install: mostlyinstall
--