bash completion: fix error introduced in cf66dfd6

cf66dfd6ba introduced a syntax error in the modified lopts string.
Without the fix, you'll provoke a shell error when trying to complete
`rebar3 ct --<something>`.

priv/shell-completion/bash/rebar3

@@ -74,8 +74,8 @@ _rebar3()
             --multiply_timetraps \
             --scale_timetraps \
             --create_priv_dir \
-            --verbose" \
-            --auto_compile
+            --verbose \
+            --auto_compile"
     elif [[ ${prev} == deps ]] ; then
         :
     elif [[ ${prev} == dialyzer ]] ; then