Switch back to -Os instead of -Oz for arm

Seems that there are still issues (segfault on ruby at least).

build-package.sh

@@ -612,9 +612,13 @@ termux_step_setup_toolchain() {
 
 	if [ -n "$TERMUX_DEBUG" ]; then
 		CFLAGS+=" -g3 -O1 -fstack-protector --param ssp-buffer-size=4 -D_FORTIFY_SOURCE=2"
+	else
+		if [ $TERMUX_ARCH = arm ]; then
+			CFLAGS+=" -Os"
 		else
 			CFLAGS+=" -Oz"
 		fi
+	fi
 
 	export CXXFLAGS="$CFLAGS"
 	export CPPFLAGS="-I${TERMUX_PREFIX}/include"