add debug logging

src/http/modules/perl/ngx_http_perl_module.c

diff --git a/src/http/modules/perl/ngx_http_perl_module.c b/src/http/modules/perl/ngx_http_perl_module.c
index a5f27dc..95483ab 100644
--- a/src/http/modules/perl/ngx_http_perl_module.c
+++ b/src/http/modules/perl/ngx_http_perl_module.c
@@ -363,6 +363,9 @@
     ctx->filename.data = NULL;
     ctx->redirect_uri.len = 0;
 
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                   "perl variable done");
+
     return rc;
 }
 
@@ -443,6 +446,8 @@
     ctx->redirect_uri.len = 0;
     ctx->ssi = NULL;
 
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "perl ssi done");
+
     return rc;
 }