update dlhttp

.gitmodules

@@ -31,3 +31,6 @@
 [submodule "deps/doctest"]
 	path = deps/doctest
 	url = https://github.com/doctest/doctest
+[submodule "deps/dlhttp"]
+	path = deps/dlhttp
+	url = https://github.com/lionkor/dlhttp

deps/CMakeLists.txt

@@ -2,6 +2,13 @@ include_directories("${PROJECT_SOURCE_DIR}/deps")
 include_directories("${PROJECT_SOURCE_DIR}/deps/commandline")
 
 add_subdirectory("${PROJECT_SOURCE_DIR}/deps/commandline")
+if (NOT TARGET fmt)
     add_subdirectory("${PROJECT_SOURCE_DIR}/deps/fmt")
+endif()
+if (NOT TARGET sol2)
     add_subdirectory("${PROJECT_SOURCE_DIR}/deps/sol2")
+endif()
+if (NOT TARGET doctest)
     add_subdirectory("${PROJECT_SOURCE_DIR}/deps/doctest")
+endif()
+add_subdirectory("${PROJECT_SOURCE_DIR}/deps/dlhttp")