Revert "add more debuggin info to the thread-safe-resolver.rkt planet test to try to debug it on drdr"

I think I know why this test is failing now; no need for this info anymore

This reverts commit e88c8dbaa0.

collects/planet/private/resolver.rkt

@@ -175,12 +175,6 @@ See the scribble documentation on the planet/resolver module.
   (case-lambda
     [(name) (void)]
     [(spec module-path stx load? orig-paramz)
-     (when (show-planet-resolver-invocations)
-       (eprintf "resolver invoked: ~s ~s\n" spec module-path)
-       (for ([x (in-list (continuation-mark-set->context (current-continuation-marks)))])
-         (eprintf "  ~s\n" x))
-       (eprintf "\n"))
-     
      ;; ensure these directories exist
      (try-make-directory* (PLANET-DIR))
      (try-make-directory* (CACHE-DIR))
@@ -191,8 +185,6 @@ See the scribble documentation on the planet/resolver module.
                      load?
                      orig-paramz)]))
 
-(define show-planet-resolver-invocations (make-parameter #f))
-
 (require racket/tcp
          racket/port
          racket/match
@@ -223,8 +215,7 @@ See the scribble documentation on the planet/resolver module.
          get-planet-module-path/pkg
          download?
          install?
-         (struct-out exn:fail:planet)
-         show-planet-resolver-invocations)
+         (struct-out exn:fail:planet))
 
 ;; if #f, will not install packages and instead raise a exn:fail:install? error
 (define install? (make-parameter #t))

collects/planet/resolver.rkt

@@ -4,5 +4,4 @@
          resolve-planet-path
          install? 
          download?
-         get-planet-module-path/pkg
-         show-planet-resolver-invocations)
+         get-planet-module-path/pkg)

collects/tests/planet/thread-safe-resolver.rkt

@@ -1,14 +1,10 @@
 #lang racket/base
 (require planet/util
          rackunit
-         racket/port
-         planet/resolver)
+         racket/port)
 
 (define debug? #t)
 
-(when debug?
-  (show-planet-resolver-invocations #t))
-
 (define (install-one package-spec key)
   (define op (open-output-string))
   (parameterize ([current-output-port op]