Revert "CONTRIBUTING: attempt to fix indentation. [skip ci]" [skip ci]

This reverts commit 7f6c0ca.

That didn't fix the indentation.

Author: guyharris

CONTRIBUTING.md

@@ -89,37 +89,37 @@ and ask!
    actual test compares the current text output with the expected result
    (`sample.out`) saved from a previous version.
 
-    Any new/updated fields in a dissector must be present in a `sample.pcap` file
-    and the corresponding output file.
+   Any new/updated fields in a dissector must be present in a `sample.pcap` file
+   and the corresponding output file.
 
-    Configuration is set in `tests/TESTLIST`.
-    Each line in this file has the following format:
-    ```
-    test-name   sample.pcap   sample.out   tcpdump-options
-    ```
+   Configuration is set in `tests/TESTLIST`.
+   Each line in this file has the following format:
+   ```
+   test-name   sample.pcap   sample.out   tcpdump-options
+   ```
 
-    The `sample.out` file can be produced as follows:
-    ```
-    (cd tests && TZ=GMT0 ../tcpdump -# -n -r sample.pcap tcpdump-options > sample.out)
-    ```
+   The `sample.out` file can be produced as follows:
+   ```
+   (cd tests && TZ=GMT0 ../tcpdump -# -n -r sample.pcap tcpdump-options > sample.out)
+   ```
 
-    Or, for convenience, use `./update-test.sh test-name`
+   Or, for convenience, use `./update-test.sh test-name`
 
-    It is often useful to have test outputs with different verbosity levels
-    (none, `-v`, `-vv`, `-vvv`, etc.) depending on the code.
+   It is often useful to have test outputs with different verbosity levels
+   (none, `-v`, `-vv`, `-vvv`, etc.) depending on the code.
 
 11) Test using `make check` (current build options) and `./build_matrix.sh`
-    (a multitude of build options, build systems and compilers). If you can,
-    test on more than one operating system. Don't send a pull request until
-    all tests pass.
+   (a multitude of build options, build systems and compilers). If you can,
+   test on more than one operating system. Don't send a pull request until
+   all tests pass.
 
 12) Try to rebase your commits to keep the history simple.
-    ```
-    git fetch upstream
-    git rebase upstream/master
    ```
-    (If the rebase fails and you cannot resolve, issue `git rebase --abort`
-    and ask for help in the pull request comment.)
+   git fetch upstream
+   git rebase upstream/master
+   ```
+   (If the rebase fails and you cannot resolve, issue `git rebase --abort`
+   and ask for help in the pull request comment.)
 
 13) Once 100% happy, put your work into your forked repository using `git push`.