Stop harmless warnings from aborting the build. When always building with the latest
toolchain and libraries, this makes the build far too brittle.

Index: sendip-2.5/Makefile
===================================================================
--- sendip-2.5/Makefile
+++ sendip-2.5/Makefile	2014-09-14 21:18:52.252614390 +0000
@@ -9,7 +9,7 @@
 #INSTALL=/usr/ucb/install
 
 CFLAGS=	-fPIC -fsigned-char -pipe -Wall -Wpointer-arith -Wwrite-strings \
-			-Wstrict-prototypes -Wnested-externs -Winline -Werror -g -Wcast-align \
+			-Wstrict-prototypes -Wnested-externs -Winline -g -Wcast-align \
 			-DSENDIP_LIBS=\"$(LIBDIR)\"
 #-Wcast-align causes problems on solaris, but not serious ones
 LDFLAGS=	-g -rdynamic -lm