Add whitespace [no ci]

doc/source/admin/jobs.md

@@ -89,7 +89,7 @@ For containerized execution the environment setup done by ``file`` and ``exec``
 not be available in the container, but only to the pre-and-post-tool-execution job environment.
 Instead, for containerized destinations variables that should only be available in the container
 can be set with ``<param id="docker_env_VARIABLE">VALUE</param>`` and
-``<param id="singularity_env_VARIABLE">VALUE</param>``,respectively.
+``<param id="singularity_env_VARIABLE">VALUE</param>``, respectively.
 
 ### Job resubmission