gsl: update to version 2.5

The current gsl recipe's PV is 1.15 which is already quite dated. The 1.15 was
released back in the 2011. The most recent one is 2.5 released in June 2018.

There are no dependencies on gsl in the oe-core / meta-oe so upgrading major
from 1 to 2 should not break anything.

Signed-off-by: Łukasz Łaguna <lukasz.laguna@3mdeb.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>

meta-oe/recipes-support/gsl/gsl_1.15.bb

@@ -1,7 +0,0 @@
-include gsl.inc
-
-SRC_URI = "${GNU_MIRROR}/gsl/gsl-${PV}.tar.gz"
-
-SRC_URI[md5sum] = "494ffefd90eef4ada678c306bab4030b"
-SRC_URI[sha256sum] = "85b907e57902e2b7606ef3aef960302ffdd13bd9dc5b8fcbfa75e4f0bf340ea3"
-

meta-oe/recipes-support/gsl/gsl_2.5.bb

@@ -0,0 +1,6 @@
+include gsl.inc
+
+SRC_URI = "${GNU_MIRROR}/gsl/gsl-${PV}.tar.gz"
+
+SRC_URI[md5sum] = "52fcbe147ba413d78841084cb43c95fb"
+SRC_URI[sha256sum] = "0460ad7c2542caaddc6729762952d345374784100223995eb14d614861f2258d"