fix: fix typo in line display of exceptions (#1912)

### Description

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### QC
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* [x] The PR contains a test case for the changes or the changes are
already covered by an existing test case.
* [x] The documentation (`docs/`) is updated to reflect the changes or
this is not necessary (e.g. if the change does neither modify the
language nor the behavior or functionalities of Snakemake).

snakemake/exceptions.py

@@ -23,7 +23,7 @@ def format_error(
 
     location = ""
     if lineno and snakefile:
-        location = f"in line {lineno} of {snakefile}"
+        location = f" in line {lineno} of {snakefile}"
         if rule:
             location = f" in rule {rule} {location}"