Merge pull request #3156 from easyeffects-bot/update-7de542c

Update gsl-2.7.1.tar.gz to 2.8

Author: wwmm

util/flatpak/easyeffects-modules.json

@@ -288,8 +288,8 @@
             "sources": [
                 {
                     "type": "archive",
-                    "url": "https://ftp.gnu.org/gnu/gsl/gsl-2.7.1.tar.gz",
-                    "sha256": "dcb0fbd43048832b757ff9942691a8dd70026d5da0ff85601e52687f6deeb34b",
+                    "url": "https://ftp.gnu.org/gnu/gsl/gsl-2.8.tar.gz",
+                    "sha256": "6a99eeed15632c6354895b1dd542ed5a855c0f15d9ad1326c6fe2b2c9e423190",
                     "x-checker-data": {
                         "type": "anitya",
                         "project-id": 1267,