move g_test_dbg_lock_sleep from a global to a function level static

This avoids the need to define that variable in every program
which uses epee.

tests/core_proxy/core_proxy.cpp

@@ -62,8 +62,6 @@ using namespace crypto;
 
 BOOST_CLASS_VERSION(nodetool::node_server<cryptonote::t_cryptonote_protocol_handler<tests::proxy_core> >, 1);
 
-unsigned int epee::g_test_dbg_lock_sleep = 0;
-
 int main(int argc, char* argv[])
 {
 

tests/core_tests/chaingen_main.cpp

@@ -44,8 +44,6 @@ namespace
   const command_line::arg_descriptor<bool>        arg_test_transactions           = {"test_transactions", ""};
 }
 
-unsigned int epee::g_test_dbg_lock_sleep = 0;
-
 int main(int argc, char* argv[])
 {
   TRY_ENTRY();

tests/functional_tests/main.cpp

@@ -55,8 +55,6 @@ namespace
   const command_line::arg_descriptor<size_t> arg_test_repeat_count = {"test_repeat_count", "", 1};
 }
 
-unsigned int epee::g_test_dbg_lock_sleep = 0;
-
 int main(int argc, char* argv[])
 {
   TRY_ENTRY();

tests/net_load_tests/clt.cpp

@@ -628,8 +628,6 @@ TEST_F(net_load_test_clt, permament_open_and_close_and_connections_closed_by_ser
   ASSERT_EQ(RESERVED_CONN_CNT, m_tcp_server.get_config_object().get_connections_count());
 }
 
-unsigned int epee::g_test_dbg_lock_sleep = 0;
-
 int main(int argc, char** argv)
 {
   epee::debug::get_set_enable_assert(true, false);

tests/net_load_tests/srv.cpp

@@ -213,8 +213,6 @@ namespace
   };
 }
 
-unsigned int epee::g_test_dbg_lock_sleep = 0;
-
 int main(int argc, char** argv)
 {
   //set up logging options

tests/performance_tests/main.cpp

@@ -42,8 +42,6 @@
 #include "generate_key_image_helper.h"
 #include "is_out_to_acc.h"
 
-unsigned int epee::g_test_dbg_lock_sleep = 0;
-
 int main(int argc, char** argv)
 {
   set_process_affinity(1);

tests/unit_tests/main.cpp

@@ -32,8 +32,6 @@
 
 #include "include_base_utils.h"
 
-unsigned int epee::g_test_dbg_lock_sleep = 0;
-
 int main(int argc, char** argv)
 {
   epee::debug::get_set_enable_assert(true, false);