claws-mail: add curl dependency
* it's needed by libetpan:
| configure:20812: checking whether libetpan-config hints compiles and links fine
| configure:20826: arm-oe-linux-gnueabi-gcc -march=armv5te -marm -mthumb-interwork --sysroot=sysroots/qemuarm -o conftest -O2 -pipe -g -feliminate-unused-debug-types -Wno-unused-function -Wno-pointer-sign -Wall -Wl,-O1 -Wl,--hash-style=gnu -Wl,--as-needed conftest.c -lm -Lsysroots/qemuarm/usr/lib -letpan -pthread -Wl,-O1 -Wl,--hash-style=gnu -Wl,--as-needed -lcurl -lgcrypt -lgnutls -lz -lexpat -lgnutls -llockfile >&5
| sysroots/x86_64-linux/usr/libexec/armv5te-oe-linux-gnueabi/gcc/arm-oe-linux-gnueabi/4.8.1/ld: error: cannot find -lcurl
| collect2: error: ld returned 1 exit status
(From meta-openembedded rev:
a016cee4c883613dbb1d922e82354f2c0c9032fe)
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
Signed-off-by: Patrick Ohly <patrick.ohly@intel.com>