config_parser: Allow modifying Parser map

This makes it possible to mutate the map owned by the parser. This will
eventually be used for implementing write updates.

Change-Id: I89deb4073a0a3bd59528c6b70fc55b49bc6cd944
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/src/util.cpp b/src/util.cpp
index 724eae6..cad1ed8 100644
--- a/src/util.cpp
+++ b/src/util.cpp
@@ -366,7 +366,7 @@
 
 bool getIPv6AcceptRA(const config::Parser& config)
 {
-    auto value = config.getMap().getLastValueString("Network", "IPv6AcceptRA");
+    auto value = config.map.getLastValueString("Network", "IPv6AcceptRA");
     if (value == nullptr)
     {
         auto msg = fmt::format(
@@ -391,7 +391,7 @@
 
 EthernetInterfaceIntf::DHCPConf getDHCPValue(const config::Parser& config)
 {
-    const auto value = config.getMap().getLastValueString("Network", "DHCP");
+    const auto value = config.map.getLastValueString("Network", "DHCP");
     if (value == nullptr)
     {
         auto msg =