Unbundles embedded-json-signature dependency.

patch bdunahu <bdunahu@operationnull.com>.

diff --git a/3rdparty/CMakeLists.txt b/3rdparty/CMakeLists.txt
index 46c0c26e1..98caaf676 100644
--- a/3rdparty/CMakeLists.txt
+++ b/3rdparty/CMakeLists.txt
@@ -54,8 +54,13 @@ set_property(TARGET re2 PROPERTY XCODE_ATTRIBUTE_GCC_WARN_ABOUT_MISSING_FIELD_IN
 set_property(TARGET re2 PROPERTY XCODE_ATTRIBUTE_GCC_WARN_SHADOW NO)	# -Wshadow
 set_property(TARGET re2 PROPERTY XCODE_ATTRIBUTE_WARNING_CFLAGS "-Wno-missing-field-initializers -Wno-shadow")
 
-add_subdirectory(EmbeddedJSONSignature EXCLUDE_FROM_ALL)
-set_property(TARGET EmbeddedJSONSignature PROPERTY FOLDER "3rdparty")
+find_path(EJS_INC NAMES EmbeddedJSONSignature.h)
+find_library(EJS_LIB NAMES EmbeddedJSONSignature)
+add_library(EmbeddedJSONSignature UNKNOWN IMPORTED)
+set_target_properties(EmbeddedJSONSignature PROPERTIES
+	IMPORTED_LOCATION "${EJS_LIB}"
+	INTERFACE_INCLUDE_DIRECTORIES "${EJS_INC}"
+)
 
 if(ENABLE_DISCORD)
 	add_subdirectory(discord-rpc EXCLUDE_FROM_ALL)