cleanup warnings in rasnet

[Dimitar Misev]

Thousands of lines in the rasdaman.install.log are populated by warnings from compiling source:rasmgr_x/src/messages/rasmgrmess.pb.h, source:rasnet/messages/client_rassrvr_service.pb.h, source:rasnet/messages/rasmgr_client_service.pb.h, etc. It'd be really great to get rid of most of these and have a more manageable log file as a result. Below is a sample, the full log file is attached in this ticket.

    "33 LDFLAGS=-L/usr/lib64/hdf/ LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/lib64/hdf/ make": {
        "code": 0, 
        "user": "rasdaman", 
        "err": "ar: creating /opt/rasdaman/source/third_party/bin/gmock/libgmock.a
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
\r  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0\r 61 2116k   61 1306k    0     0  5254k      0 --:--:-- --:--:-- --:--:-- 5248k\r100 2116k  100 2116k    0     0  7457k      0 --:--:-- --:--:-- --:--:-- 7454k
+ autoreconf -f -i -Wall,no-obsolete
parallel-tests: installing 'build-aux/test-driver'
parallel-tests: installing 'build-aux/test-driver'
configure.ac:60: installing './ar-lib'
configure.ac:41: installing './config.guess'
configure.ac:41: installing './config.sub'
configure.ac:43: installing './install-sh'
configure.ac:43: installing './missing'
conformance/Makefile.am: installing './depcomp'
parallel-tests: installing './test-driver'
+ rm -rf autom4te.cache config.h.in~
+ exit 0
ldconfig: Can't create temporary cache file /etc/ld.so.cache~: Permission denied
ldconfig: Can't create temporary cache file /etc/ld.so.cache~: Permission denied
In file included from client.cc:29:0:
../../rasmgr_x/src/messages/rasmgrmess.pb.h: In member function \u2018void rasmgr::DefineServerGroup::set_allocated_group_name(std::string*)\u2019:
../../rasmgr_x/src/messages/rasmgrmess.pb.h:4718:82: warning: declaration of \u2018group_name\u2019 shadows a member of 'this' [-Wshadow]
 inline void DefineServerGroup::set_allocated_group_name(::std::string* group_name) {
                                                                                  ^
../../rasmgr_x/src/messages/rasmgrmess.pb.h: In member function \u2018void rasmgr::DefineServerGroup::set_allocated_host(std::string*)\u2019:
../../rasmgr_x/src/messages/rasmgrmess.pb.h:4771:70: warning: declaration of \u2018host\u2019 shadows a member of 'this' [-Wshadow]
 inline void DefineServerGroup::set_allocated_host(::std::string* host) {
                                                                      ^
../../rasmgr_x/src/messages/rasmgrmess.pb.h: In member function \u2018void rasmgr::DefineServerGroup::set_allocated_db_host(std::string*)\u2019:
../../rasmgr_x/src/messages/rasmgrmess.pb.h:4854:76: warning: declaration of \u2018db_host\u2019 shadows a member of 'this' [-Wshadow]
 inline void DefineServerGroup::set_allocated_db_host(::std::string* db_host) {