Merge branch 'sg/trace2-rename'

Dev support update to help tracing out tests.

* sg/trace2-rename:
  trace2: correct typo in technical documentation
  Revert "test-lib: whitelist GIT_TR2_* in the environment"

Author: gitster

Documentation/technical/api-trace2.txt

@@ -35,7 +35,7 @@ Format details are given in a later section.
 === The Normal Format Target
 
 The normal format target is a tradition printf format and similar
-to GIT_TRACE format.  This format is enabled with the `GIT_TR`
+to GIT_TRACE format.  This format is enabled with the `GIT_TRACE2`
 environment variable or the `trace2.normalTarget` system or global
 config setting.
 

t/test-lib.sh

@@ -386,7 +386,6 @@ unset VISUAL EMAIL LANGUAGE COLUMNS $("$PERL_PATH" -e '
 	my @env = keys %ENV;
 	my $ok = join("|", qw(
 		TRACE
-		TR2_
 		DEBUG
 		TEST
 		.*_TEST