mesalib: Update version from 19.2.2 to 19.3.1

1.  https://www.mesa3d.org/relnotes/19.3.0.html
2.  https://www.mesa3d.org/relnotes/19.3.1.html

mesalib.be0

@@ -1,6 +1,6 @@
 #!/usr/bin/env beesh
 
-# BEE_VERSION mesalib-19.2.2-0
+# BEE_VERSION mesalib-19.3.1-0
 
 ## this file was created by bee init and should be executed to build a
 ## bee-package. (Additional hints are located at the end of this file.)