!2 Completing build dependencies

From: @hht8
Reviewed-by: @small_leek
Signed-off-by: @small_leek

potrace.spec

@@ -1,13 +1,13 @@
 Name:           potrace
 Version:        1.15
-Release:        5
+Release:        6
 Summary:        Utility for Tracing a Bitmap to Scalable Outline Image
 License:        GPLv2+
 URL:            http://potrace.sourceforge.net
 Source0:        http://downloads.sourceforge.net/%{name}/%{name}-%{version}.tar.gz
 Source1:        http://potrace.sourceforge.net/potrace.pdf
 Source2:        http://potrace.sourceforge.net/potracelib.pdf
-BuildRequires:  zlib-devel
+BuildRequires:  zlib-devel gcc
 
 %description
 Potrace(TM) is a tool for tracing a bitmap, which means, transforming a bitmap into a smooth, scalable image.
@@ -66,5 +66,8 @@ cp -a %{SOURCE2} .
 %{_mandir}/man1/mkbitmap.1.*
 
 %changelog
+* Mon May 31 2021 huanghaitao <huanghaitao8@huawei.com> - 1.15-6
+- Completing build dependencies
+
 * Thu Dec 12 2019 wutao <wutao61@huawei.com> - 1.15-5
 - Package init