main/sipcalc: fix license expression

This package is licensed under the BSD-3-Clause license. Currently the
license is specified as BSD which is not a valid SPDX identifier and
ambiguous.

main/sipcalc/APKBUILD

@@ -2,11 +2,11 @@
 # Maintainer: ScrumpyJack <scrumpyjack@st.ilet.to>
 pkgname=sipcalc
 pkgver=1.1.6
-pkgrel=3
+pkgrel=4
 pkgdesc="Advanced console based ip subnet calculator"
 url="https://www.routemeister.net/projects/sipcalc/"
 arch="all"
-license="BSD"
+license="BSD-3-Clause"
 options="!check" # no tests
 subpackages="$pkgname-doc"
 source="https://www.routemeister.net/projects/sipcalc/files/sipcalc-$pkgver.tar.gz"