don't override UA AMALGAMATION ARCHITECTURES

CMakeLists.txt

@@ -65,10 +65,10 @@ mark_as_advanced(UA_AMALGAMATION_ARCHITECTURES)
 set(UA_ARCHITECTURE "None" CACHE STRING "Architecture to build open62541 on")
 
 if(UA_ENABLE_AMALGAMATION)
-    if(NOT "${UA_ARCHITECTURE}" STREQUAL "None")
-        set(UA_AMALGAMATION_ARCHITECTURES "${UA_ARCHITECTURE}")
-    else()
-        if("${UA_AMALGAMATION_ARCHITECTURES}" STREQUAL "")
+    if("${UA_AMALGAMATION_ARCHITECTURES}" STREQUAL "")
+        if(NOT "${UA_ARCHITECTURE}" STREQUAL "None")
+            set(UA_AMALGAMATION_ARCHITECTURES "${UA_ARCHITECTURE}")
+        else()
             # select some default architectures which should be included
             set(UA_AMALGAMATION_ARCHITECTURES "win32;posix")
         endif()