Reverted to latest WCSlib now that C++ compilation error is fixed

Author: cschreib

doc/scripts/install.sh

@@ -40,7 +40,7 @@
 INSTALL_ROOT_DIR=""
 
 CFITSIO_VERSION="_latest"
-WCSLIB_VERSION="-5.20"
+WCSLIB_VERSION=""
 VIF_VERSION="master"
 EGG_VERSION="latest"