fix join operation error (#555) (#556)

Co-authored-by: FWuellhorst <[email protected]>

Author: mwetter

buildingspy/development/merger.py

@@ -343,8 +343,7 @@ def merge(self, overwrite_reference_results=False):
 
         # Iterate over the list of files to be copied.
         copiedFiles = list()
-        for fil in filesToCopy:
-            srcFil = os.path.join(root, fil)
+        for srcFil in filesToCopy:
             # Loop over all
             # - .mo files except for top-level .mo file
             # - .mos files