WARN instead of ERROR if java does not run. Caused issue on OS X w/out real java installed

m4/ac_prog_java_works.m4

@@ -57,7 +57,7 @@ if test x$ac_cv_prog_uudecode_base64 != xyes; then
 	rm -f Test.class
 	AC_MSG_WARN([I have to compile Test.class from scratch])
 	if test x$ac_cv_prog_javac_works = xno; then
-		AC_MSG_ERROR([Cannot compile java source. $JAVAC does not work properly])
+		AC_MSG_WARN([Cannot compile java source. $JAVAC does not work properly])
 	fi
 	if test x$ac_cv_prog_javac_works = x; then
 		AC_PROG_JAVAC
@@ -83,7 +83,7 @@ if test x$ac_cv_prog_uudecode_base64 != xyes; then
 	else
 		echo "configure: failed program was:" >&AC_FD_CC
 		cat $JAVA_TEST >&AC_FD_CC
-		AC_MSG_ERROR(The Java compiler $JAVAC failed (see config.log, check the CLASSPATH?))
+		AC_MSG_WARN(The Java compiler $JAVAC failed (see config.log, check the CLASSPATH?))
 	fi
 fi
 																									       if AC_TRY_COMMAND($JAVA $JAVAFLAGS $TEST) >/dev/null 2>&1; then
@@ -91,7 +91,7 @@ fi
 else
 	echo "configure: failed program was:" >&AC_FD_CC
 	cat $JAVA_TEST >&AC_FD_CC
-	AC_MSG_ERROR(The Java VM $JAVA failed (see config.log, check the CLASSPATH?))
+	AC_MSG_WARN(The Java VM $JAVA failed (see config.log, check the CLASSPATH?))
 fi
 rm -fr $JAVA_TEST $CLASS_TEST Test.uue])
 AC_PROVIDE([$0])dnl