fix toml license string

Author: tcgoetz

pyproject.toml

@@ -14,7 +14,7 @@ readme = "README.md"
 license = {text = "GPL"}
 classifiers = [
     "Development Status :: 5 - Production/Stable",
-    "License :: OSI Approved :: GPL",
+    "License :: OSI Approved :: GNU General Public License v2 (GPLv2)",
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",
     "Programming Language :: Python :: 3.12",