mesalib: rebuild for correct linkage against llvm 6.0.0

Since the update to llvm 6.0.0 als mesa drivers under
/usr/lib/dri where defunct (libLLVM-4.0.so => not found).
Workstations using the drivers from nvidia are not affected.

- en passant: update to 17.3.9
- note ahead: mesalib-18.1.5 fails
- fail Requested 'libdrm >= 2.4.91' but version of libdrm is 2.4.89
- fail Requested 'libdrm_amdgpu >= 2.4.91' but version of
libdrm_amdgpu is 2.4.89

mesalib.be0

@@ -1,6 +1,6 @@
 #!/usr/bin/env beesh
 
-# BEE_VERSION mesalib-17.3.3-0
+# BEE_VERSION mesalib-17.3.9-0
 
 ## 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.)