fix missing isnan from merge conflicts

nicHoch · nicHoch · commit 1322f4cdca99 · 2025-09-30T14:07:54.000+02:00
diff --git a/stixcore/io/fits/processors.py b/stixcore/io/fits/processors.py
@@ -39,8 +39,7 @@
 
 
 def empty_if_nan(val):
-    return "" if isnan(val) else val
-
+    return "" if np.isnan(val) else val
 
 
 def version_format(version):
