assimp: Don't set -Werror

Have to do this with a patch rather than just updating to v5.2.5 and relying on ASSIMP_WARNINGS_AS_ERRORS since that one doesn't build on Android

CMakeLists.txt

@@ -259,6 +259,8 @@ if(BUILD_ASSIMP)
     GIT_REPOSITORY https://github.com/assimp/assimp.git
     GIT_TAG 8134cae998ec0e3a44a6ec8330b681f3981107b7 #v5.1.6
 
+    PATCH_COMMAND patch -p1 < ${CMAKE_CURRENT_LIST_DIR}/patches/assimp-5.1.6-no-werror.patch
+
     CMAKE_ARGS ${COMMON_CMAKE_ARGS}
       -DCMAKE_PREFIX_PATH=${THIRDPARTY_DIR}/zlib
       -DASSIMP_BUILD_TESTS=OFF

patches/assimp-5.1.6-no-werror.patch

@@ -0,0 +1,25 @@
+diff --git a/code/CMakeLists.txt b/code/CMakeLists.txt
+index 08efd28df..e7cab6dc6 100644
+--- a/code/CMakeLists.txt
++++ b/code/CMakeLists.txt
+@@ -1168,7 +1168,6 @@ TARGET_USE_COMMON_OUTPUT_DIRECTORY(assimp)
+ IF (MSVC)
+   TARGET_COMPILE_OPTIONS(assimp PRIVATE /WX)
+ ELSE()
+-  TARGET_COMPILE_OPTIONS(assimp PRIVATE -Werror)
+ ENDIF()
+
+ # adds C_FLAGS required to compile zip.c on old GCC 4.x compiler
+diff --git a/contrib/zip/CMakeLists.txt b/contrib/zip/CMakeLists.txt
+index bba4e7bde..98842b5e5 100644
+--- a/contrib/zip/CMakeLists.txt
++++ b/contrib/zip/CMakeLists.txt
+@@ -45,7 +45,7 @@ if (MSVC)
+ elseif ("${CMAKE_C_COMPILER_ID}" STREQUAL "GNU" OR
+         "${CMAKE_C_COMPILER_ID}" STREQUAL "Clang" OR
+         "${CMAKE_C_COMPILER_ID}" STREQUAL "AppleClang")
+-  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=gnu99 -Wall -Wextra -Werror -pedantic -Wno-deprecated")
++  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=gnu99 -Wall -Wextra -pedantic -Wno-deprecated")
+ endif (MSVC)
+
+ ####