abuild: use $SUDO instead of 'sudo'

So SUDO="sudo -E" works for http proxy settings

abuild.in

@@ -1249,13 +1249,13 @@ post_add() {
 
 installdeps() {
 	local deps i
-	sudo $APK add --wait 30 --repository "$abuildrepo" \
+	$SUDO $APK add --wait 30 --repository "$abuildrepo" \
 		--virtual .makedepends-$pkgname \
 		$makedepends
 }
 
 uninstalldeps (){
-	sudo $APK del .makedepends-$pkgname
+	$SUDO $APK del .makedepends-$pkgname
 }
 
 all() {