Disable mpfr detection to fix a build error due to (unncessary)
missing dependency:
```
Package gawk is missing dependencies for the following libraries:
libgmp.so.10
libmpfr.so.6
```
Signed-off-by: Tianling Shen <cnsztl@immortalwrt.org>
(cherry picked from commit
3d9b6df7d8f4ee52721bbd0693795367d987eb7d)
PKG_NAME:=gawk
PKG_VERSION:=5.2.1
-PKG_RELEASE:=1
+PKG_RELEASE:=2
PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.xz
PKG_SOURCE_URL:=@GNU/gawk
DEPENDS:=+libncursesw +libreadline
endef
+CONFIGURE_ARGS+= --disable-mpfr
+
define Package/gawk/install
$(INSTALL_DIR) $(1)/usr/bin
$(CP) $(PKG_INSTALL_DIR)/usr/bin/gawk $(1)/usr/bin/