[cppcheck] fix all 3 errors

Signed-off-by: Raphael Defosseux <raphael.defosseux@eurecom.fr>

src/nrf_app/nrf_config.hpp

@@ -75,7 +75,7 @@ class nrf_config {
   unsigned int sbi_http2_port;
   std::string sbi_api_version;
   // Local configuration
-  bool local_configuration;
+  bool local_configuration = false;
 
   nrf_config() : m_rw_lock(), pid_dir(), instance(0), sbi() {
     sbi.port        = 80;

src/nrf_app/nrf_search_result.hpp

@@ -43,6 +43,8 @@ class nrf_search_result {
  public:
   nrf_search_result() {
     limit_nf_instances = 10;  // default value, TODO: to be removed
+    validity_period = 0;
+    num_nf_inst_complete = 0;
   };
   nrf_search_result(nrf_search_result const&) = delete;