fix serverlist implementation error, fix postgres find, fix pkg-config missing from ci build

* closes https://codeberg.org/minenux/minetest-engine-minetest/issues/25
* related https://codeberg.org/minenux/minetest-engine-multicraft2/issues/46

src/CMakeLists.txt

@@ -211,8 +211,8 @@ if(ENABLE_POSTGRESQL)
 		set(USE_POSTGRESQL TRUE)
 		message(STATUS "PostgreSQL backend enabled")
 		# This variable is case sensitive, don't try to change it to POSTGRESQL_INCLUDE_DIR
-		message(STATUS "PostgreSQL includes: ${PostgreSQL_INCLUDE_DIR}")
-		include_directories(${PostgreSQL_INCLUDE_DIR})
+		message(STATUS "PostgreSQL includes: ${PostgreSQL_INCLUDE_DIRS}")
+		include_directories(${PostgreSQL_INCLUDE_DIRS})
 	else()
 		message(STATUS "PostgreSQL not found!")
 	endif()

src/serverlist.cpp

@@ -32,6 +32,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include <json/json.h>
 #include "convert_json.h"
 #include "httpfetch.h"
+#include "util/base64.h"
 #include "util/string.h"
 
 namespace ServerList