[#3025] fix missing include

src/bin/perfdhcp/avalanche_scen.h

@@ -11,6 +11,7 @@
 
 #include <perfdhcp/abstract_scen.h>
 
+#include <unordered_map>
 
 namespace isc {
 namespace perfdhcp {

src/bin/perfdhcp/test_control.h

@@ -27,7 +27,6 @@
 #include <random>
 #include <string>
 #include <vector>
-#include <unordered_map>
 
 namespace isc {
 namespace perfdhcp {

src/lib/mysql/mysql_connection.cc

@@ -20,6 +20,7 @@
 #include <exception>
 #include <limits>
 #include <string>
+#include <unordered_map>
 
 using namespace isc;
 using namespace isc::asiolink;

src/lib/pgsql/pgsql_connection.cc

@@ -15,6 +15,7 @@
 #include <util/file_utilities.h>
 
 #include <exception>
+#include <unordered_map>
 
 // PostgreSQL errors should be tested based on the SQL state code.  Each state
 // code is 5 decimal, ASCII, digits, the first two define the category of