Remove redundant includes in minizip.
diff --git a/contrib/minizip/unzip.c b/contrib/minizip/unzip.c
index 366e1f8..ed763f8 100644
--- a/contrib/minizip/unzip.c
+++ b/contrib/minizip/unzip.c
@@ -77,8 +77,6 @@
 
 #ifdef STDC
 #  include <stddef.h>
-#  include <string.h>
-#  include <stdlib.h>
 #endif
 #ifdef NO_ERRNO_H
     extern int errno;
diff --git a/contrib/minizip/zip.c b/contrib/minizip/zip.c
index 7facc23..3d3d4ca 100644
--- a/contrib/minizip/zip.c
+++ b/contrib/minizip/zip.c
@@ -32,8 +32,6 @@
 
 #ifdef STDC
 #  include <stddef.h>
-#  include <string.h>
-#  include <stdlib.h>
 #endif
 #ifdef NO_ERRNO_H
     extern int errno;