bug 385745, breakpad landing broke --disable-compile-environment, r=luser

configure.in

@@ -5365,7 +5365,7 @@ if test -n "$MOZ_AIRBAG"; then
        fi
     fi
 
-    if test -z "$_CURL_FOUND"; then
+    if test -z "$_CURL_FOUND" && test -z "$SKIP_LIBRARY_CHECKS"; then
         AC_MSG_ERROR([Couldn't find libcurl, which is required for the crash reporter.  Use --disable-airbag to disable the crash reporter.])
     fi
   fi