do not delete keys from dict

python/dune/perftool/blockstructured/transformations.py

@@ -19,7 +19,6 @@ def blockstructured_iname_duplication(kernel):
             for s in suffixes:
                 if base + s in duplication_options:
                     dup_kernel = duplicate_inames(dup_kernel, base + s, duplication_options[base + s])
-                    del duplication_options[base + s]
             if has_schedulable_iname_nesting(dup_kernel):
                 return dup_kernel