Fix for Boost 1.78

New Boost does not revert iterators in some cases, so reverting must be
done manually.

About the command_completion change: I have no idea, but the 1.77 fix
works for 1.78.

This actually needs this patch
https://github.com/boostorg/spirit/pull/711. No idea how to inject that
to the CI.

Issue: https://github.com/boostorg/spirit/issues/703#issuecomment-1011021773
Change-Id: I2d1266b1f8b893f180ae36842bdfdb35c5629ea4
diff --git a/tests/command_completion.cpp b/tests/command_completion.cpp
index 8e8570f..96b115b 100644
--- a/tests/command_completion.cpp
+++ b/tests/command_completion.cpp
@@ -19,6 +19,7 @@
     std::ostringstream errorStream;
     std::set<std::string> expectedCompletions;
     int expectedContextLength;
+
     SECTION("no prefix")
     {
         expectedCompletions = {"cd", "copy", "create", "delete", "set", "commit", "get", "ls", "discard", "help", "describe", "move", "dump", "prepare", "exec", "cancel", "switch"};