`make install` fails

[doitian]

It passes the same file twice to install command.

/usr/bin/install -c -m 644 include/secp256k1.h include/secp256k1_ecdh.h include/secp256k1_recovery.h include/secp256k1_recovery.h '/usr/local/include'
/usr/bin/install: will not overwrite just-created '/usr/local/include/secp256k1_recovery.h' with 'include/secp256k1_recovery.h'
Makefile:1151: recipe for target 'install-includeHEADERS' failed
make[1]: *** [install-includeHEADERS] Error 1
make[1]: Leaving directory '/home/travis/secp256k1'
Makefile:1578: recipe for target 'install-am' failed
make: *** [install-am] Error 2

[doitian]

It seems introduced in 91fae3a

[doitian]

Reproduce:

./configure --enable-module-recovery