Allow parallel make

contrib/gitian/gitian-linux.yml

@@ -153,7 +153,7 @@ script: |
     export PATH=${BASEPREFIX}/${i}/native/bin:${ORIGPATH}
     mkdir build && cd build
     cmake .. -DCMAKE_TOOLCHAIN_FILE=${BASEPREFIX}/${i}/share/toolchain.cmake -DBACKCOMPAT=ON
-    make
+    make ${MAKEOPTS}
     DISTNAME=monero-${i}
     mv bin ${DISTNAME}
     find ${DISTNAME}/ | sort | tar --no-recursion --mode='u+rw,go+r-w,a+X' --owner=0 --group=0 -c -T - | gzip -9n > ${OUTDIR}/${DISTNAME}.tar.gz

contrib/gitian/gitian-osx.yml

@@ -100,7 +100,7 @@ script: |
     export PATH=${BASEPREFIX}/${i}/native/bin:${ORIGPATH}
     mkdir build && cd build
     cmake .. -DCMAKE_TOOLCHAIN_FILE=${BASEPREFIX}/${i}/share/toolchain.cmake
-    make
+    make ${MAKEOPTS}
     DISTNAME=monero-${i}
     mv bin ${DISTNAME}
     find ${DISTNAME}/ | sort | tar --no-recursion --mode='u+rw,go+r-w,a+X' --owner=0 --group=0 -c -T - | gzip -9n > ${OUTDIR}/${DISTNAME}.tar.gz

contrib/gitian/gitian-win.yml

@@ -125,7 +125,7 @@ script: |
     export PATH=${BASEPREFIX}/${i}/native/bin:${ORIGPATH}
     mkdir build && cd build
     cmake .. -DCMAKE_TOOLCHAIN_FILE=${BASEPREFIX}/${i}/share/toolchain.cmake
-    make
+    make ${MAKEOPTS}
     DISTNAME=monero-${i}
     mv bin ${DISTNAME}
     find ${DISTNAME}/ | sort | zip -X@ ${OUTDIR}/${DISTNAME}.zip