[Proxy] Refactor proxy server caching implementation - breaks compilation

[adriansev]

with the head set to 1339e37 i see this :

creating build/temp.linux-x86_64-3.7/home/adrian/GIT-REPOS/xrootd/bindings/python/src
/usr/lib64/ccache/cc -pthread -Wno-unused-result -Wsign-compare -DDYNAMIC_ANNOTATIONS_ENABLED=1 -DNDEBUG -O2 -g -pipe -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 -Wp,-D_GLIBCXX_ASSERTIONS -fexceptions -fstack-protector-strong -grecord-gcc-switches -m64 -mtune=generic -fasynchronous-unwind-tables -fstack-clash-protection -fcf-protection -D_GNU_SOURCE -fPIC -fwrapv --std=c++0x -fPIC -I/home/adrian/GIT-REPOS/xrootd/src -I/home/adrian/GIT-REPOS/xrootd/xrootdbuild/src -I/usr/include/python3.7m -c /home/adrian/GIT-REPOS/xrootd/bindings/python/src/PyXRootDModule.cc -o build/temp.linux-x86_64-3.7/home/adrian/GIT-REPOS/xrootd/bindings/python/src/PyXRootDModule.o -g
/usr/bin/ld: /usr/lib/gcc/x86_64-redhat-linux/9/../../../../lib64/libXrdPosix.so: undefined reference to `vtable for XrdOucCacheDram'
collect2: error: ld returned 1 exit status
make[2]: *** [src/api_test/CMakeFiles/xrd_api_test.dir/build.make:88: src/api_test/xrd_api_test] Error 1
make[1]: *** [CMakeFiles/Makefile2:1165: src/api_test/CMakeFiles/xrd_api_test.dir/all] Error 2
make[1]: *** Waiting for unfinished jobs...

[abh3]

I believe we fixed this as we don't see this problem. Please reopen if this is still an issue.