Remove highlighting in bug-loc test...

We really ensre that highlighting is in effect, and highlighting markup
is fragile

test/data/bug-loc.right

@@ -1,26 +1,26 @@
 (bug-loc.sh:5):
-5:	dirname=${BASH_SOURCE%/*}   # equivalent to dirname($0)
+5:	dirname=${BASH_SOURCE%/*}   # equivalent to dirname($0)
 +# Test to see that we read in files that mentioned in breakpoints
 +# but we don't step into.
-+step
++step 
 (bug-loc.sh:6):
-6:	source ${dirname}/library.sh
-+step
+6:	source ${dirname}/library.sh
++step 
 (bug-loc.sh:7):
-7:	echo 'script line 7'
-+step
+7:	echo 'script line 7'
++step 
 script line 7
 (bug-loc.sh:8):
 8:	library-function
-+step
++step 
 (library.sh:1):
 1:	library-function() {
-+step
++step 
 (library.sh:2):
-2:	  echo 'library line 2 in library-function'
-+step
+2:	  echo 'library line 2 in library-function'
++step 
 library line 2 in library-function
 (bug-loc.sh:11):
-11:	echo 'script line 11'
-+quit
+11:	echo 'script line 11'
++quit 
 bashdb: That's all, folks...

test/integration/test-bug-loc

@@ -9,7 +9,7 @@ t=${0##*/}; TEST_NAME=${t:5}   # basename $0 with 'test-' stripped off
 debugged_script="$top_srcdir/test/example/bug-loc.sh"
 
 if ( pygmentize --version || pygmentize -V ) 2>/dev/null 1>/dev/null ; then
-    run_debugger_opts="-B -q --no-init --highlight=light"
+    run_debugger_opts="-B -q --no-init --no-highlight"
     run_test_check $TEST_NAME $TEST_NAME $debugged_script
 else
     exit 77