Make CMake fail when libQuotient version is newer than 0.6

CMakeLists.txt

@@ -74,6 +74,10 @@ set_package_properties(Quotient PROPERTIES
     PURPOSE "Talk with matrix server"
 )
 
+if(${Quotient_VERSION_MINOR} GREATER 6)
+    message(SEND_ERROR "NeoChat cannot be compiled against a 0.7 version of libQuotient. Use a 0.6 version instead")
+endif()
+
 find_package(cmark)
 set_package_properties(cmark PROPERTIES
     TYPE REQUIRED