3rdparty: remove optional submodule

.gitmodules

@@ -26,9 +26,6 @@
 	url = https://github.com/RPCS3/hidapi
 	branch = master
 	ignore = dirty
-[submodule "3rdparty/Optional"]
-	path = 3rdparty/Optional
-	url = https://github.com/akrzemi1/Optional.git
 [submodule "3rdparty/pugixml"]
 	path = 3rdparty/pugixml
 	url = https://github.com/zeux/pugixml

.travis.yml

@@ -55,7 +55,7 @@ install:
      fi;
 
 before_script:
-  - git submodule update --init asmjit 3rdparty/ffmpeg 3rdparty/pugixml 3rdparty/GSL 3rdparty/libpng 3rdparty/cereal 3rdparty/hidapi 3rdparty/Optional 3rdparty/xxHash 3rdparty/yaml-cpp Vulkan/glslang
+  - git submodule update --init asmjit 3rdparty/ffmpeg 3rdparty/pugixml 3rdparty/GSL 3rdparty/libpng 3rdparty/cereal 3rdparty/hidapi 3rdparty/xxHash 3rdparty/yaml-cpp Vulkan/glslang
   - mkdir build ; cd build
   - if [ "$TRAVIS_PULL_REQUEST" = false ]; then
       export CXXFLAGS="$CXXFLAGS -DBRANCH=$TRAVIS_REPO_SLUG/$TRAVIS_BRANCH";

appveyor.yml

@@ -49,7 +49,6 @@ install:
       3rdparty/GSL `
       3rdparty/hidapi `
       3rdparty/libpng `
-      3rdparty/Optional `
       3rdparty/pugixml `
       3rdparty/xxHash `
       3rdparty/yaml-cpp `

rpcs3/CMakeLists.txt

@@ -328,7 +328,6 @@ ${LLVM_INCLUDE_DIRS}
 "${RPCS3_SRC_DIR}/../3rdparty/GL"
 "${RPCS3_SRC_DIR}/../3rdparty/stblib"
 "${RPCS3_SRC_DIR}/../3rdparty/cereal/include"
-"${RPCS3_SRC_DIR}/../3rdparty/Optional"
 "${RPCS3_SRC_DIR}/../3rdparty/discord-rpc/include"
 "${RPCS3_SRC_DIR}/../3rdparty/xxHash"
 "${RPCS3_SRC_DIR}/../3rdparty/GPUOpen/include"